ST Albans MP Anne Main has been invited to apologise and asked to pay back thousands of pounds in public money for allowing her daughter to live rent-free at her second home.
The Parliamentary Standards Committee ruled Mrs Main had breached the rules by allowing her daughter to stay in her taxpayer-funded pad in Samuel Square, Pageant Close, St Albans.
Mrs Main claimed thousands of pounds in mortgage repayments and a council discount even though her 24-year-old daughter, Claire Tonks, had been staying there more frequently than herself over a three year period.
Following a report into MPs' second home expenses by parliamentary standards commissioner John Lyon, Mrs Main was ordered to repay £7,100 in respect of the period between November 2006 and April 2009, when Miss Tonks had been living at the flat.
Mrs Main, whose main home is just 20 miles from her constituency in Beaconsfield, was also found to have flouted parliamentary guidelines by claiming more than £2,000 for meals eaten away from her main home. Her expenses claims included food bills for meals in Westminster.
In his report, Mr Lyon stated that while it is acceptable for an MP's children and family to share a designated second home, it is not permissable for an independent adult to reside at the expense of the public purse.
Mr Lyon said: "On any interpretation of the evidence, Mrs Main's daughter is an independent adult. She could have been expected to have been reponsible for her own living costs.
"It was entirely a matter for Mrs Main whether she subsidised those costs, for example by not charging her adult daughter rent when she stayed in the family's Beaconsfield home.
"There was nothing unusual in that: many other parents do the same. But it does not follow that the same principle should apply to parliamentary-funded accommodation.
"Public funds should not have been expected to meet the living costs of Mrs Main's adult daughter when she stayed in the St Albans flat. That should have been a private matter for the family. It should not have been a matter for public funds."
Mrs Main has been forced to apologise and repay the overclaimed expenses.
However, the backbench MP refused to accept that allowing her daughter to stay at the flat for 'moral support' was punishable.
In evidence to the standards committee, Mrs Main said: "I am very disappointed that the commissioner does not accept a mother's desire to see her daughter for part of the time as natural but that he chooses to describe it as an 'emotional benefit' and that he believes it is a benefit I should somehow pay for it.
"The emotional benefit was to me as a parent. we could have mother and daugter time and spend time together. There was no financial benefit, and she didn't need to be there, but it helped me in my role having her there sometimes, as it freed up my time to serve to my constituents."
Charles Bunker, deputy chairman of the Conservative Party in the Eastern Region, told the Review St Albans Tories would remain supportive of Mrs Main as the party's candidate in the impending General Election, despite today's revelations.
However, rival politician, Liberal Democrat parliamentary hopeful Sandy Walkington, who will go head to head with Mrs Main in the polls in May, said: "Ultimately I just don't think any member of Parliament for St Albans needs a second home. This morning everyone was going to the station leaving their own home, and catching a train to work and commuting home - that's the way it works. St Albans is a communting constituency and an MP shouldn't be any different."
Mr Walkington's Labour counterpart Roma Mills added: "It's good to see that this has been resolved. It's good to see the process has been transparent and obviously effective.
"It's a great lesson for the future for all of us in public life - be very clear about why you claim and what you claim in terms of expenses. It's right that they should be in the public forum."