Labour must focus on policy and not infighting over its leadership to win the next election, Prime Minister Tony Blair has warned.
In his first public speech since saying he would step down within a year, he said Labour was "ideologically united" despite the "spasm" of the last week.
The comments come as former Home Secretary Charles Clarke criticised the PM's likely successor Gordon Brown.
Mr Blair later flew to the Middle East to meet Israeli PM Ehud Olmert.
Earlier Mr Blair said attacks within the party "turns the public off".
He was making a keynote speech at the 10th anniversary conference of a New Labour think tank, the Progress Organisation, in central London.
"We're three years away from an election and we can remake ourselves," he said.
But Mr Blair said this could only be achieved "by behaving like we did when we were hungry for power before 1997".
He said the party then understood the country and not itself mattered.
"We can either - after the kind of spasm of last week retreat into personal attacks... or we can say we are going in a mature, intelligent, and capable way to describe to the country what we've done," he said.
Mr Blair said the government needed to address "difficult issues" such as the welfare state, global warming, security and migration.
"What the people out there want to know are the answers to their difficult questions and the challenges of their lives," he said.
"What they don't want is to see a whole lot of politicians talking to themselves. So we go out, face out to the people, we succeed. We face inward - we lose."
Mr Blair was speaking before arriving in Israel for talks on restarting the Middle East peace process.
He was asked later at a joint press conference with Israeli Prime Minister Ehud Olmert whether he regretted his support of President George W Bush in the Middle East, now that he had announced his plans to leave office.
He said: " "I don't think it has ever been a mistake to stand shoulder to shoulder with America in the aftermath of 9/11."
Before Mr Blair's departure for the Middle East, Cabinet ministers Douglas Alexander and Harriet Harman lined up to urge the party to stop fighting and get behind the chancellor.
The speech came as Mr Brown was criticised again by Charles Clarke
A handful of anti-war protesters were involved in scuffles with police when Mr Blair arrived for the speech as they tried to get past barriers.
Three men were arrested for violent disorder and are being held at a north London station, Scotland Yard said.
Mr Blair's attempt to heal wounds within the party came amid mounting speculation about the end of his tenure as prime minister.
Mr Clarke launched another attack on Mr Brown on Saturday. He accused him of being a "control freak", lacking the courage to take tough decisions and being "deluded" about his relationship with the prime minister.
"He is totally, totally uncollegiate", he told the Daily Telegraph.
His comments came after his earlier interview with the Evening Standard in which he accused Mr Brown of "absolutely stupid" behaviour during the furore over the leadership.
Northern Ireland Secretary Peter Hain described Mr Clarke's comments as "quite extraordinary" and said Mr Brown would be an "excellent successor".
"What has been going on in the past week is an absolute and total disgrace," he said.
"People are fed up to the back teeth of senior figures kicking lumps out of each together. It has got to stop and it has got to stop now."