International Development Secretary Priti Patel is not being investigated over meetings she held with an Israeli politician and a charity reportedly without telling the Foreign Office, Downing Street said.
Theresa May's official spokesman said Ms Patel was in Israel on a private holiday "paid for by herself" and "no investigation" is being carried out into whether she broke ministerial rules.
She was backed by Foreign Secretary Boris Johnson, who said the pair "work closely together" and that she was "quite right" to have the meetings, despite the BBC reporting that she had broken convention by failing to tell his department, which is in charge of UK foreign policy.
The Liberal Democrats accused Ms Patel of making a "grave error of judgment" by pursuing personal ambition with the meetings, and demanded to know whether she had broken the ministerial code.
But the Prime Minister's spokesman told reporters: "I think while she was there she took the opportunity to meet some people and organisations but it was a private holiday and entirely paid for by the Secretary of State."
"I've not been made aware of any concerns," he added. "No investigation is taking place."
Mr Johnson tweeted: ".@Patel4witham is a good friend & we work closely together for GLOBAL BRITAIN. Quite right that she meets w/ people & organisations overseas".
It comes after the minister was pictured meeting Yair Lapid, the leader of Israel's centrist Yesh Atid party, while on the holiday.
Mr Lapid tweeted a photo of the meeting on August 24 and described Ms Patel as a "true friend of Israel".
According to the BBC, Ms Patel was accompanied by Tory peer Lord Polak, who is honorary president of the Conservative Friends of Israel lobbying group.
The pair also visited Beit Issie Shapiro, an Israeli disability charity and campaign group, according to the BBC.
Lib Dem international development spokeswoman Baroness Sheehan said: "Priti Patel has made a grave error of judgment, which goes against the openness, accountability and scrutiny the work of a Government minister demands.
"The Department for International Development is facing a litany of disasters around the world in which UK aid will play a key role in recovery and rebuilding. Shockingly, in the face of that responsibility, the Secretary of State has seemingly swanned off to Israel to pursue her personal career.
"It is objectionable that Priti Patel chooses to use her position of influence to inappropriately foster her own political ambition, disregarding both common courtesy due to the Foreign Secretary and Government procedures.
"Priti Patel now must answer questions over whether she has broken the ministerial code of conduct. If she has, her position as Secretary of State is untenable."