HOUNSLOW MPs Ann and Alan Keen finally admitted for the first time this week they use their controversial housing allowance to pay the mortgage on a central London flat.

The MPs, who have netted nearly £200,000 of taxpayers' money under the Additional Costs Allowance (ACA) since 2001, confirmed they own a flat 'within walking distance of Parliament'.

The political duo told the Chronicle they use the allowance - available to cover the housing costs of MPs with constituencies outside inner London - to meet mortgage payments on the property.

Although they have broken no rules, critics accuse the pair of 'skating on thin moral ice' for claiming on a second home when their constituency base is just nine miles from Westminster.

But Mr Keen, MP for Feltham and Heston, defended the allowance.

"If these people shadowed us from morning until night then they might feel differently," he said.

"Ann gets her red ministerial box at Westminster when most of us are going to bed, and it would be hard for her to get back to Brentford for four or five hours sleep."

Mr Keen revealed death threats made by a disgruntled constituent to Ann outside their Brentford home two years ago had an impact on the health minister.

The Brentford and Isleworth MP - whose son Mark is openly gay - also received 'foul, crude, sexual' drawings and letters after she voted in favouring of lowering the age of consent for homosexual men.

Mr Keen added: "Ann has been bullied by people and some of it's been disgraceful. It's an understatement to say she's felt insecure."

Details of the couple's expenses between 2001 and 2004 were revealed in a national newspaper at the weekend.

It showed they provided no receipts for the ACA in 2001/02 and 2002/03, but gave a breakdown of £17,669.26 both received in 2003/04. The duo each spent over £5,000 on mortgage payments, more than £1,000 on service charges and a further £10,000 on 'other' things.

Mr Keen admitted he 'did not know' what this sum represented but insisted all the claims made under the ACA went towards the costs of the flat.

Lib Dem Parliamentary candidate Cllr Andrew Dakers called on the couple to release detailed receipts of previous claims.

He insisted Mrs Keen's promotion to ministerial level had come 'long after' their decision to purchase a central London flat.

He added: "It's barking mad they can't jump on a train back to Brentford. They're skating on thin moral ice."