Michael Howard has appealed to Tories to unite behind him now he has been crowned party leader.
The ex-home secretary won a one horse race
The ex-home secretary was speaking after winning the one-horse race to replace Iain Duncan Smith - ousted last week in a confidence vote.
The appointment was confirmed by Sir Michael Spicer, chairman of the backbench 1922 committee after no rivals came forward.
And it subsequently emerged the board of the Conservative Party was not planning to have a vote of the entire membership to ratify Mr Howard's appointment.
Instead there will be an "informal consultation" of members over the weekend.
The former home secretary immediately thanked his Conservative colleagues for giving him the "immense privilege" of leading the party.
Mr Howard addressed Tory MPs in the Commons after his appointment was confirmed.
He urged them to unite after the splits which plagued Mr Duncan Smith's leadership, saying: "We must rediscover the habit of thinking the best of each other."
Mr Howard said: "It is an immense privilege to lead this party - the most successful party in the history of modern democracy. But it is also a truly awesome responsibility.
"I will work tirelessly not to let you down. But I will make mistakes. And I will inevitably at times upset some of you.
"And when that happens - indeed even when it does not happen - there are things we will need to remember. That we are a party broad and generous; broad in appeal and generous in outlook."
He went on: "If we are to win we must work together as a team. We must rediscover the habit of thinking the best of each other. We must rediscover the virtues of mutual support and friendship.
"Because we have an extraordinary common thread that binds us all together. We all want to see a Conservative Government elected.
"We are all crew on what at its best is the most superb campaigning vessel politics has ever known."
A statement from the Conservative Board said: "The Board has received overwhelming representations from the Party at large, and, in line with these representations, has decided not to initiate a formal postal ratification ballot.
"There will be an informal consultation of party members over the weekend to give the voluntary party the opportunity to show, like the parliamentary party, that it is fully united behind the new Leader."
Mr Howard's elevation to leader was welcomed by Tory former prime minister John Major.
"I warmly congratulate Michael Howard and wish him well," he said.
"He is the best choice for the party and the country
and deserves the support of all present Conservative voters and the millions of others now so disillusioned with Labour."
Current Tory chairman Theresa May said she was "delighted".
"I look forward to working with Michael and doing all I can to ensure that this party is ready to win the next general election," she said
Mr Howard's campaign chief, Liam Fox, said: "I am absolutely delighted. I think it is the beginning of the real resurgence
in Conservative fortunes.
"The government might rightly now contemplate the end of their days."
Mr Howard, who was Mr Duncan Smith's shadow chancellor, was addressing MPs privately, before celebrating in public with a speech at a parish hall in Putney, a marginal constituency in south west London.
He told MPs they must focus their efforts on getting rid of the Labour government.
There must be "no bystanders, no snipers from the sidelines. Everyone of us a fully engaged participant in the great battle of hears and minds and ideas", he said.
Mr Howard had the support of more than 130 of the 165 Tory MPs, his campaign team said.
Mr Duncan Smith: No carping
There is fevered speculation about how his shadow cabinet will line up, with commentators assessing whether he may offer Tory big-hitters like Kenneth Clarke and Michael Portillo frontline jobs.
Mr Howard may announce his team on Friday, or wait until after the weekend.
Health Secretary John Reid was quick to brand the new Tory leader as "Mr Poll Tax" and he highlighted Mr Howard's opposition to the minimum wage and record when he was a minister in previous Conservative administrations.
But Tory MP Eleanor Laing said: "Tony Blair and his immediate colleagues are terrified of a Michael Howard-led party."
Liberal Democrat leader Charles Kennedy said: "I do not think (Mr Howard's)
confirmation makes a great deal of difference to the Tory Party or to British