John McCain wrapped up the Republican convention tonight by reaching out beyond the party faithful to the independents who will determine in November whether he or Barack Obama is the next occupant of the White House.

After formally accepting the Republican presidential nomination, he used his prime-time speech to try to steal from his Democratic rival the theme of change, a potent message in an election year in which voters are disillusioned with the George Bush presidency, the Iraq war and the state of the economy.

"Let me offer an advance warning to the old, big spending, do nothing, me first, country second Washington crowd: change is coming," he said.

Warming to his theme of shaking up Washington, McCain appeared to borrow a phrase from the British prime minister John Major's last years in power saying he would take the Republican "back to basics".

Touching on another theme popular with independents, he promised to end the "constant partisan rancour" that has left Washington so often deadlocked.

McCain, the self-styled maverick who has so often angered his own party by bucking the party line, was given a five-minute standing ovation at the start of his 50-minute speech and again at the end, as confetti and 200,000 balloons floated from the ceiling, the traditional convention finish.

But, a poor orator who has made few - if any - memorable speeches in the past, he failed to match either the rhetoric of Obama in Denver last week or even the feisty, sarcastic delivery of his own running mate, Sarah Palin.

Some of the loudest cheers of the night were when Palin, the new darling of the Republican party, joined him at the end.

Although the organisers said the theme of the day was "peace," the tone of videos shown earlier in the night as well as in his speech and those of others was heavily militaristic. McCain devoted a large part of his speech to one of his biggest selling points, the period that turned him into an American hero, his five years in a Hanoi jail after his plane crashed on a bombing mission. As an admiral's son, he was offered the chance of early release but turned it down, refusing preferential treatment.

The passage on his prison years, which seldom fails to resonate with Americans, earned him four standing ovations, to chants of "USA, USA".

His time in jail, he said, turned him into a super-patriot. "I fell in love with my country when I was a prisoner in someone else's … I was never the same again. I wasn't my own man anymore. I was my country's."

The speech was a high point for McCain, aged 72, who was watched by his mother, Roberta, aged 96, and comes a year after he almost had to pull out of the Republican nomination with his campaign close to bankruptcy.

McCain, ignoring the sustained personal - and frequently misleading - attacks on Obama at the convention, chose to present himself as above such tactics, saying he admired his Democratic rival for his achievement in winning his party's nomination. "Despite our differences, much more unites us than divides us," he said, to applause. "We are fellow Americans, an association that means more to me than any other."

McCain, aware of his limitations as a speaker, attempted to recreate the intimacy of the townhall meetings with which he is more comfortable by placing the podium in the middle of the audience, but it was a failed experiment, with his delivery as deadening as ever.

The start of his speech was briefly marred by protesters, including one from military veterans opposed to him.

He used the convention to try to win over the millions watching at home with his promise of a bipartisan approach to politics, saying he had a proven record of working with Democrats in the Senate, often in the face of anger from fellow Republicans. "I have the record and the scars to prove it. Senator Obama does not," McCain said.

He is friends with many Democratic senators and has sponsored various bipartisan initiatives in the Senate, including a bill to ease illegal immigration along with the Democrat Ted Kennedy, angering Republicans.

Forseeing a McCain presidency he said: "I will ask Democrats and Independents to serve with me. And my administration will set a new standard for transparency and accountability."

But pointing to other differences with the Democratic nominee, he said there was a gap between them on tax cuts, foreign policy - particularly Iraq - and drilling for oil in US waters.

He issued a warning to Russia over the conflict in Georgia. "We can't turn a blind eye to aggression and international lawlessness that threatens the peace and stability of the world and the security of the American people," he said.

One of the loudest ovations he received all night was when he spoke about Palin. "I can't wait until I introduce her to Washington. And let me offer an advance warning to the old, big spending, do nothing, me first, country second Washington crowd: change is coming," McCain said.