Gordon Brown produced arguably the most powerful speech of his political career today as he attempted to face down critics of his leadership at the Labour party conference.

In a lengthy and substantial address, the Prime Minister hammered home the message that he is the right man to lead Britain through the current economic crisis and that only Labour will take the right decisions to support hard-working families.

The Prime Minister also unveiled plans to scrap prescription charges for cancer patients and give elderly people help to stay in their homes and escape the costs of going into care. Promising "a new settlement for new times", he told delegates that his vision of a “fair society” was “a cause worth fighting for".

In a speech described by aides as “bullish”, Mr Brown admitted he had made mistakes – including on the abolition of the 10p tax rate - but insisted he has the right long-term vision for the country.

"Where I've made mistakes I'll put my hand up and try to put them right," he said. "So what happened with 10p stung me because it really hurt that suddenly people felt I wasn't on the side of people on middle and modest incomes - because on the side of hard-working families is the only place I've ever wanted to be. And from now on it's the only place I ever will be."

Mr Brown’s speech had been billed as a crucial one for the fate of his premiership, and so it may yet prove. Although he has faced little open dissent in Manchester, the gathering has been dominated by speculation over a possible future challenge.

The man seen as his most likely rival, David Miliband, the Foreign Secretary, was this morning forced to rebut reports that he had privately told an adviser he toned down his own conference speech to avoid outshining Mr Brown in a “Heseltine moment”.

Mr Brown was preceded onto the platform by his wife Sarah, who broke with tradition by introducing him to the delegates, and he went on to portray himself as an ordinary family man just trying to give his children "an ordinary childhood".

That included a barely disguised dig at David Cameron, the photogenic and family-friendly Tory leader: "Some people have been asking why I haven't served my children up for spreads in the papers and my answer is simple: my children aren't props; they're people."

Interrupted repeatedly by increasingly warm applause, Mr Brown set out a range of plans to help voters with issues ranging from prescription charges to care for the elderly, free nursery education for two-year-olds and linking disadvantaged schoolchildren up to the internet.

He told delegates that over the next year, prescription charges for all NHS drugs will be abolished for cancer patients in England, with the eventual aim of phasing out the £7.10 charge for all patients with long-term conditions. The move immediately takes around 250,000 people out of prescription charges, rising to five million in the longer term.

The change is estimated to cost £20 million over the next year, rising to £300 million a year over the long term as more conditions are covered, and is expected to save many patients £100 a year or more. It follows an announcement by the Scottish Government that it plans to phase out all prescription charges by 2011. Prescriptions are already free in Wales.

Times Recommends

• Oh no, Mr Darling: you have failed
• BBC survives dogfight over Kennel Club expose
• Where the Rosetta belongs can’t be set in stone