Obama kicks off London visit by urging Brits to vote against Brexit in June referendum

US President Barack Obama arrived in London on Thursday with a mission - to persuade British voters not to ditch membership of the European Union in a referendum that Washington fears could weaken the West.

Obama is urging Britons to vote to stay in the European Union, saying the challenges in the world require allies to “stick together.”

In an op-ed published in the Telegraph newspaper, Obama says Great Britain’s presence in the EU “magnifies” Britain’s influence and helps spread “British values.”

Obama writes he’s offering his view “with the candour of a friend” and notes the decision will affect US interests.

The piece was published Thursday evening as Obama arrived in London for a three-day visit. Some have speculated that the trip is timed to boost the campaign against the so-called “Brexit” ahead of a June referendum.

The US government - and many US banks and companies - fear a Brexit would unleash market turmoil, diminish British clout, undermine London’s status as a global financial capital, cripple the EU and undermine Western security.

For Britain’s closest ally, EU membership amplifies British influence, facilitates trade for US companies and strengthens the 28-member bloc which Washington views as a pillar of stability in the post-World War Two era.

Opinion polls indicated that British voters are leaning towards the ”In” camp in the June 23 referendum, but many remain undecided.

Asked about Obama’s views, Cameron told the parliament:

”Personally I believe we should listen to advice from friends and other countries and I struggle to find the leader of any friendly country who thinks we should leave.”

Not all Britons are welcoming Obama’s opinion. New York-born Boris Johnson, the London mayor who heads the “Out” campaign, said he did not want to be lectured by Americans about EU membership.

”President Obama should butt out,” Nigel Farage, another prominent opponent of EU membership, told Reuters.

Obama’s term in office ends next Jan. 20. On Friday he will have lunch at Windsor Castle with Queen Elizabeth, who celebrated her 90th birthday on Thursday, and her husband Prince Philip. After lunch, Obama will hold talks with Cameron.