Boris Johnson offers his top tips for next UK prime minister

Outgoing British prime minister signs off with a flourish, telling MPs: 'Hasta la vista, baby'

Britain's Prime Minister Boris Johnson described holding the office as the 'greatest privilege of my life'. AFP

Boris Johnson defended his time in government and outlined advice for his successor as he attended his final session of Prime Minister's Questions in parliament on Wednesday.

Mr Johnson, who is expected to stand down in September, declared “mission largely accomplished” before signing off by telling MPs: “Hasta la vista, baby.”

He was cheered and clapped by members of his party as he walked out of the House of Commons chamber for the final time as leader of the Conservatives.

In a closing address, Mr Johnson gave advice to his ultimate successor, who he said should "stay close to America" and "stick up" for Ukraine and global democracy.

He also urged the next British prime minister to "cut taxes and deregulate wherever you can to make this the greatest place to live and invest".

"Focus on the road ahead, but always remember to check the rear-view mirror and remember above all it’s not Twitter that counts", he said.

Mr Johnson, 58, said his time in office had been "the greatest privilege" of his life.

"I helped to get the biggest Tory majority for 40 years and a huge realignment in UK politics," he said.

"I’ve helped to get this country through a pandemic and helped save another country from barbarism, and frankly that’s enough to be going on with.

"Mission largely accomplished."

Mr Johnson was admonished after calling opposition leader Sir Keir Starmer a “great pointless human bollard” as he fended off attacks from the opposition over his conduct and economic record.

Speaker Sir Lindsay Hoyle urged MPs to conduct Prime Minister’s Questions in a manner “focusing on issues and policies rather than personalities”.

The House of Commons breaks for its summer recess on Thursday, and the new leader is expected to be announced when it reconvenes on September 5.

Labour leader Keir Starmer quoted the bitter attacks hurled against each other and their own government's record by the three remaining Conservative candidates: Rishi Sunak, Liz Truss and Penny Mordaunt.

"I'm not following this thing particularly closely," the prime minister said of the Tory race, to laughter.

But he praised Mr Sunak's economic management during the pandemic, and said that any one of the three, "like some household detergent, would wipe the floor" with Labour.

The Conservative race has eliminated successive candidates in ballots among the party's MPs.

The final two will be chosen later on Wednesday, before taking their case to grassroots Tories during August.