I've been enjoying this mini series – the first in Channel 4's Big Food Fight season. I did wonder whether it was going to be a super-worthy, preachy sick fest, but Hugh Fearnley Whittingstall's likeable enthusiasm has really carried through, and his clever and effective was of educating his local town of Axminster has provided some really good, heartwarming and touching moments.

We're here at the end of the series. We left Tuesday's show on the cusp – he had made a huge town-wide appeal, was still trying to pin down some representatives from the big supermarkets for a serious chat about chickens, and the crew from the Millway council estate were to experience killing the birds they had become so attached to.

Part three and it was straight into the action. HFW was walking the streets, trying to convince people that his Chicken Out campaign was worth signing up for. Some were into it, some accused him of guilt tripping.

Meanwhile, back at the shed, he invited the people of Axminster along to see the intensively-reared chickens. Again, some people – after seeing the now fattened birds – were appalled, while some people couldn't care less and argued that for people without too much money in their pockets these chickens were the only option.

But time was running out for HFW's intensive chickens – 39 days had passed and it was time for them to go to slaughter. The feeders were taken away, the lights were turned down and chicken removal people moved in (yes, people who do these jobs do exist). It was horrible. By darkness they grabbed the legs and put them into crates. It was like watching a war movie – prisoners led away to the firing line.

Never again, said HFW. Never again.

But things started to look up. He finally got a response from one of the supermarkets. Representatives from Sainsbury's came down to Axminster to have a chat, and promised to start working with Hugh. Result! But HFW was after Tesco's – the biggest and most popular supermarket in the town. He had managed to persuade one of the managers to hang some posters, but when he checked back he was thrown out in a comic episode ("Don't swear at me... don't be an arsehole," said the deputy manager). He was also banned from filming at the Co-Op.

Unabated, HFW kicked off Chicken Out week with an intense round of publicity. He did radio and TV interviews, supplied the local fast food outlets with some of his free-range stock, and played films to school kids and in the local pub.

At the local boozer, there was the first sign that the wheels were just beginning to come off his campaign. His film was greeted with a biting gust of icy cynicism ("If someone is that bothered about a f****** chicken, then they or shouldn't eat them or go f****** vegetarian," said one angry drinker).

His campaign was dividing the town. Those who disagreed with him were stuck on price, and soon rumours started to circulate that HFW was charging £22 per chicken (first it was £18, then £20) in his River Cottage shop. He was suddenly being accused as a self-promoter, and one newspaper even accused him of influencing the house prices in the town. Things weren't going well. One kebab shop owner just wasn't having any of it, but he did agree to put out some free-range kebabs for an evening. This led to another comedy moment. Hugh, helping out in the kitchen and clearly getting very agitated with the guy's ambivalence, said in a voice over: "We made free-range chicken kebabs, which were marinated in Moussa's secret marinade – turmeric, lemon juice.... Revenge can be sweet.

My favourite part of the show was seeing how the Millway estate gang had developed into committed free-range chicken activists. Hayley was very quiet tonight, but the chickens the crew had been looking after in their allotment were now due to be slaughtered. Dave and jane admitted getting too attached to one of their chickens, and Dave volunteered to take out their favourite, Chuffy, when the time came. It was very emotional – they were all dreadfully upset but they were now committed to spreading the word and making sure their chicken experience wasn't in vain. There was some great TV in that sequence.

It was HFW's final push to make Axminster Britain's first free-range town. He held a mini-festival to mark the end of Chicken Out week, where he would announce the selling statistics for the week ("I'm going to look like a bit of twat if it has failed"). But good news – 60 per cent of all whole chickens sold during the week had been free range. HFW and his motley band of chicken converts HAD made a difference. It was a great moment. Hugh gave a speech (with rousing music behind it, natch) that urged people to keep it going.

And things didn't stop there – three of the big supermarkets had agreed to work with Hugh to improve their birds' housing conditions, and his campaign had been taken up in parliament.

And that was it. Three nights of chicken documentaries. But what chicken documentaries they were. HFW pushed himself to the limits and took himself out of his River Cottage comfort zone. We saw a new Hugh – emotional and sometimes sweary – but his enthusiasm and passion were inspirational. I've always like him, but some don't warm to him because of his plummy accent. But now, after this, he's just Hugh. One of us. Passionate and enthusiastic, and just Hugh.

Of course, this was just a start. On a trip to Tesco's he spotted Hayley – although part of the Millway gang, she had always been one of the most outspoken members of the 'but this is what I can afford' brigade – buying some cheap, knackered chickens. After all they had been through, she still didn't buy free range. That was her decision, but it just shows that the campaign has such a long way to go.

But arm people with information and give them the tools to do something about it, and the supermarkets will listen. They will stock food that people want to buy, it's as simple as that. And this was the thing – this documentary series wasn't about chickens (I know that sounds weird) but about people. People realising they can make a difference. People realising that they do have the power to do something. HFW just gave them the knowledge and the tools to do something about it. Right f****** on!

Hugh's Chicken Run, part 1 review here
Hugh's Chicken Run, part 2 review here