Claire Ward , youngest of the so-called "Blair Babes", travelled to New Delhi last April for the opening of the new Temple of Understanding, paid for by the International Society for Krishna Consciousness.
Local devotees met the 26-year-old Member for Watford at the airport, accompanied her through the five-day trip and funded her hotel stay. Miss Ward spoke at the temple inauguration, reading a "message of support" from Tony Blair.
Miss Ward's trip - declared in the latest Commons Register of Members' Interests, which has not yet been published - prompted accusations last night that she was supporting a "dangerous sect".
Ian Howarth, founder of the Cult Information Centre said he had been "extremely concerned" about the movement for years. "Families talk of losing loved ones to that group," he said. "For an MP to accept free flights from them is at best naive, and at worst giving credibility to an organisation that is highly controversial."
Miss Ward said she had an interest in the organisation because its Letchmore Heath centre - in a Tudor mansion donated by the former Beatle George Harrison in 1973 - bordered her constituency.
"They are not a cult, they are part of the Hindu religion and everyone has the right to worship in their religion," she said. "The fact that the Prime Minister was willing to put his name to the opening gives it credibility, it's not just me wandering off doing my own thing."
Although Miss Ward is not a Hare Krishna "believer", her interest in it dates back 10 years. Her father, Frank Ward, was one of the local councillors who campaigned for devotees to be allowed to worship at Letchmore Heath. Among its more-famous former members are Boy George and Annie Lennox,
John Gummer, the then Secretary of State for the Environment ruled in favour of the sect in 1996 after Hertsmere borough council tried to ban the centre holding festivals, which had attracted up to 20,000 people. Local residents had complained.
The Watford MP now regularly attends ceremonies there and has helped with fund-raising events. "There are a number of people who are constituents of mine who worship in the centre," she said.
Varsana Dasi, a Krishna spokeswoman, said Miss Ward had visited their temples for years. "She has more understanding of what we are about than most people," she said. "Her father fought for Letchmore Heath because he believes in freedom of worship in a place of one's choice."