LONDON (AP) — Opposition lawmakers in Britain asked Parliament's standards watchdog on Thursday to investigate who paid for Prime Minister Boris Johnson to take a luxury post-election holiday in the Caribbean.

Johnson and his partner Carrie Symonds spent an 11-day break on the island of Mustique over the New Year, after Johnson's Conservative party won Britain's Dec. 12 election.

In the Register of Members’ Interests, where lawmakers are required to disclose donations and outside earnings, Johnson claimed the couple's accommodation, valued at 15,000 pounds ($20,000), was donated by British businessman David Ross.

A spokesman for Ross, founder of mobile phone retailer Carphone Warehouse, told the Daily Mail that the businessman had helped find a villa for Johnson, but had not paid for it.

Ross later clarified in a statement that he “facilitated accommodation for Mr. Johnson on Mustique valued at 15,000 pounds. Therefore this is a benefit in kind from Mr. Ross to Mr. Johnson, and Mr. Johnson's declaration to the House of Commons is correct."

Opposition Labour Party lawmaker Jon Trickett said he had asked Parliament’s standards commissioner to investigate.

"The code of conduct requires members to provide the name of the person or organization that actually funded a donation,” Trickett said. "Transparency is crucial to ensuring that the public have confidence that elected members of this House have not been unduly influenced by any donations or gifts that they may receive.”

Johnson’s office said “all transparency requirements have been followed, as set out in the register of members' financial interests."

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