There's a bank of cameras, cars honking as they drive past and plenty of handshakes following the leader of the Greens as he walks up the high street in Levenshulme.
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He's here to talk about rejuvenating the high street in this pocket of Manchester that turned from red to green in the Gorton and Denton by-election in February. It caused a not-so-minor political earthquake on the left and Polanski is hoping to shake up a lot more in May's elections.
He tells me, as we walk down the high street in the sunshine, that Labour are going to have a "disastrous" set of local elections and that he thinks Keir Starmer will be out of Number 10 in the next couple of months.
"I don't see how he survives this set of elections.
"I just feel like there's been a sense it hasn't happened for a long time because there was no obvious successor, but you can't keep going like that.
"At some point you have to say it can't get any worse, and actually I think there's a general consensus that his poll ratings have bottomed out as low as they can go, to the point that may be the Mandelson stuff doesn't affect him as it should."
'Greens will replace Labour'
In London, Polanski could potentially win four boroughs that have long been Labour - Hackney, where Polanski lives, Lambeth, Lewisham and Waltham Forest, according to a YouGov MRP poll. Across England, Polanski's Greens are expected to gain hundreds of council seats.
He tells me the Greens are going to replace Labour. When I ask him who, should Starmer be forced out of office, he'd find the most difficult Labour character to face as his successor, that it would be Andy Burnham. "We'd be in a similar political space, but as a member of this country, I'd much rather have someone more progressive leading the government than Keir Starmer."
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But for all the talk of a green wave, Polanski's Greens seem a very long way from replacing Labour. Rather like Corbyn's Labour, Polanski's eco-populism brand has energised younger, urban and ethnic minority voters.
Party membership has grown from 50,000 when he was running for party leader to over 225,000 in the eight months since he's had the job. It's impressive on any measure.
The question for Polanski, as it was for Farage's Reform as it began the transition from being a party of protest to one seriously vying for power, is how to put together policies and people to appeal to a wider group of voters: when I sat down with him in the local park in Levenshulme, I wanted to know how the Green Party bridges that gap.
For now, the Greens seem to be following a 50-seat strategy in a general election, pitching themselves as an alternative left party, rather than building a broader coalition by picking off voters in more traditionally Conservative areas - Herefordshire, Rossendale, Amber Valley - concerned about the environment - the type of coalition of different voters a party needs to win marginal seats.
When I ask Polanski what he's going to do to appeal to more voters, he tells me that part of it is the way the party communicates with voters. "They all know we want to protect the environment and tackle the climate crisis, that's never going to change. But I think people are less aware about our policies to tax multimillionaires and billionaires. To really tackle the fact that people have low wages and high bills."
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Where he is less comfortable is talking about defence. Polling shows that over one in two voters don't trust the Greens on defence - and when I ask Polanski about his approach to NATO, he veers away from the party policy to remain a member of NATO, he gives me a much more nuanced answer when I ask him if he wants to leave the security alliance. "I want us to create an alternative alliance to have that discussion."
When I press him again about wanting to leave, he tells me: "Not immediately, once we get an alternative alliance with our European neighbours, so we can ensure our military, our security, then to start working towards that alternative alliance."
His argument is that NATO is not working because Donald Trump is being "deliberately antagonistic" and that European allies should build an alternative alliance.
But on what those timeframes of exiting NATO and building this new alliance with European countries (already in NATO) are, he's less clear. It doesn't seem to me to be very thought-through policy on a matter of such importance, as Western allies face wars on two fronts - in Ukraine and the Middle East.
The Polanski factor
There's also Polanski himself. The leader undoubtedly has huge appeal, knows how to work social media in the attention economy and is a fluent communicator. But here are questions around his leadership and judgement.
This week, he provoked alarm among the Jewish community when he said of the horrific wave of anti-semitic attacks: "There's a conversation to be had about whether it's a perception of unsafety or whether it's actual unsafety, but neither are acceptable."
That phrase - the "perception of unsafety" - was seized upon by many in the Jewish community as somehow downplaying the rise of antisemitism Jewish people are experiencing and the way the community is feeling. When I put that to Polanski, he told me: "Neither are acceptable, and that's why I said that. And look, this context is I'm one of five Jewish people who have ever led a political party in British history."
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When I also put it to Polanski that for some talking of a "perception of unsafety" was somehow downplaying these attacks, he said: "Those people would be taking me out of context and doing it for their own particular political reasons. What I think I'm saying is very clear, that both arsons and dressing up an artificial image of a Jewish leader dressed as a Nazi is also unacceptable. One is actually making Jewish people unsafe, and one is a perception of unsafety.
"Of course, as a Jewish man, I care about antisemitism."
Keir Starmer said Polanski's comments were "disgraceful" as antisemitism was "very real" and "felt throughout the whole community".
On his judgement, one other thing I could not shake was why he did an interview with the Sun newspaper in 2013, claiming he could hypnotise a woman into having bigger breasts. It was a long time ago, when he was 30 years old and before he was in politics - but when I dug out the article and read it, I found it such an odd thing to do and I wanted to understand why he did it.
First, he told me the article was nonsense, but when I pushed back and pointed out that there were direct quotes from him in the article and he endorsed it a few days after it was published on a BBC radio show, he then admits "it was the Sun journalist's idea and I should have said no".
"I wasn't a politician; I went along with the idea. I shouldn't have done it and that's what I've apologised for," he added.
When I ask him what he says to those voters looking at this and women who might find it uncomfortable, he tells me: "I do appreciate you asking me the question because ultimately I do want to speak to those women, but that article doesn't represent me. It was a wrong thing to do to go along with a Sun journalist, that's why I apologised, that is why I'll continue to apologise. But I think when people look at my record as a politician, not just as leader of the Green Party, but the last few years as an elected member of the London Assembly, I've got a strong record of working with women on women's rights.
"I understand how people can look at the history and go 'that was strange'. I often think about what Tony Benn said, which is 'I don't care where you came from, I care where you're going' and I stand by that apology, but I think most people are interested right now in what I and the Green Party are doing."
Polanski tells me, for the record, he now doesn't believe that you can enlarge women's breasts through hypnotherapy. But what he does believe is that the Green Party is going to grow rapidly in the coming weeks and months. But with more success, more seats, more power, comes more scrutiny. Is Polanski and his party really ready for that?
This interview is part of a series that Sky News will be conducting with party leaders ahead of the May elections.
