Britain should 'try and be as close to the EU as we can be' - Cameron

In his final question and answer session in the House of Commons, Cameron said he would "miss the roar of the crowd and the barbs from the opposition" that came with the job over the past six years.

But, he pointed wistfully to the capricious winds of politics that had abruptly ended his career, saying: "I was the future once."

The Conservative leader quit after Britain voted to leave the European Union against his wishes.

But he had some final advice for May, his long-time interior minister who was sitting beside him.

"My advice to my successor, who is a brilliant negotiator, is that we should try to be as close to the European Union as we can be, for the benefits of trade, of co-operation and of security," he said.

Later Wednesday, Cameron will tender his resignation to Queen Elizabeth II at Buckingham Palace, after which the monarch will task May with forming a government.

The 59-year-old will be the second woman to lead Britain, following in the footsteps of fellow Conservative, "Iron Lady" Margaret Thatcher.

The steely vicar's daughter faces a daunting challenge in trying to negotiate an amicable divorce from the EU following the shock vote for Brexit on June 23.

EU leaders have said they expect May to move quickly, and French President Francois Hollande, German Chancellor Angela Merkel and Italy's Prime Minister Matteo Renzi announced they will hold a summit in August on the vote.

May has indicated however that she will not be rushed into triggering the formal procedure for Brexit.

She is expected to begin announcing her cabinet choices before the day is out, including a Brexit minister in charge of securing a new trade and travel deal with the EU.

Finance minister George Osborne, who fought alongside Cameron to remain in the union, is expected to lose his job, with May sharply critical of his legacy.

Women are expected to secure several top jobs, with current energy minister Amber Rudd and international development minister Justine Greening tipped for lead roles along with foreign minister Philip Hammond and Brexit campaigner Chris Grayling.

Friends of former London mayor Boris Johnson told The Telegraph newspaper he also hoped to play a "significant role", two weeks after he dramatically withdrew from the race to succeed Cameron.

Investors will be watching May's first days in office closely but with greater optimism since the pound, which fell by up to 15 percent against the dollar in the days after the Brexit vote, rallied this week.

May campaigned as a safe pair of hands who will help bridge Conservative Party divisions and restore investor confidence in the face of a potential economic downturn.

Her other mammoth challenges include keeping pro-EU Scotland from bidding for independence in order to stay in the 28-nation bloc, and weaving new trade and diplomatic alliances beyond the EU.

In a good-natured session of parliament, Cameron took potshots at embattled Labour leader Jeremy Corbyn, who faces a bitter leadership battle of his own.

On Wednesday, Owen Smith became the second Labour MP to announce a bid to try to oust Corbyn, who is resisting pressure to resign over his perceived lacklustre campaigning for Britain's continued EU membership.

"We got on with it, we've had resignation, nomination, competition and coronation -- they haven't even decided what the rules are yet!" Cameron said.

He bowed out with a poignant line that he used a decade ago against former Labour prime minister Tony Blair.

"As I once said, I was the future once," he said, before walking out to a standing ovation of Tory MPs.

The referendum exposed deep inequalities in British society, which May has vowed to address.

May, who campaigned half-heartedly for Britain to stay in the EU, has said "Brexit means Brexit" and vowed to "make a success of it."

A tough-talking interior minister for the past six years, May is something of an unknown quantity internationally, although she has received ringing endorsements from party colleagues and a normally sceptical British tabloid press.

The daughter of a Church of England pastor, May is a cricket fan with a sober demeanour who lists her hobbies as cooking and walking.

She is well liked in and around Maidenhead, the well-to-do commuter town west of London that she has represented in parliament since 1997.

Martin Trepte, editor of the Maidenhead Advertiser, the local newspaper, said: "She's a mature, grown-up, no-nonsense politician. She knows her stuff."