LONDON (WASHINGTON POST) - British members of Parliament are grappling with an intractable problem that's infected the fabric of political life and has no end in sight. For once, it's not Brexit.

Mice in the Palace of Westminster are so brazen that they scamper over desks in broad daylight, frequent the site's many cafes and bars and make nests out of old paperwork.

The problem has persisted for years, despite the authorities spending hundreds of thousands of pounds to contain it.

"Almost everyone has seen them scampering around and having discos," said Ms Thangam Debbonaire, a Labour MP. She recounts seeing a rodent in a House of Commons cafe while entertaining a guest last month.

"Whilst we were eating our cake, a mouse ran over my foot and then just sat there nibbling crumbs. It wasn't intimidated," she said. "The next day, I took another guest to a different cafe and again, there was a mouse there in the middle of the day."

The authorities spent £119,000 (S$213,000) in the 2017-2018 financial year to contain mice, moths, rats and other pests on the Parliamentary estate, which as well as the 19th-century Houses of Parliament, includes Portcullis House, a building that opened in 2001, and a collection of smaller, neighbouring buildings.

Expenditure in the five years through 2018 topped £500,000.

Ms Debbonaire's not alone. Conservative lawmakers Andrew Bowie and Robert Halfon both said they had mice run over their feet while frequenting Parliament's numerous eateries.

Mr Halfon said mice in his office recently ate through a box of tea. He said he's stopped keeping food there and even makes sure not to leave empty coffee cups in the bin.

"A couple of years ago, I walked into my office and my team were standing on tables screaming. We had to vacate the office for a few days," he said. "My head of office found a dead one on her desk a few days ago."

Aside from the health and hygiene implications of having mice running around Parliament, there's a safety risk because the rodents can chew through electrical cables, heightening the risk of fire in Victorian buildings that are already in need of extensive refurbishment.

The current plan is for elected politicians to move out of Westminster in the mid 2020s for a major restoration programme.

It isn't just mice that need to be controlled: moths threaten to ruin upholstery on antique furniture and historic carpets created by A.W. Pugin, a 19th-century designer.

An infestation last year led Mr Richard Gilbey, known as Lord Vaux of Harrowden, to lament in the House of Lords: "I worry that if I sit still for too long in this Chamber, I will stand up to discover that my clothes have been turned to lace."

The House of Commons said in an e-mailed statement that the proximity of Parliament to the River Thames makes it "particularly vulnerable to pests, especially to mice", a problem made worse in recent years by building work.

"The House of Commons employs a full-time pest control technician, who will continue to take all necessary measures to control the pest population."

There are mousetraps in corridors, meeting rooms and offices, while in the chamber of the House of Lords, moth traps are on display.

Rat traps are also deployed, and pest controllers pay for hawks that deter pigeons and seagulls from nesting and roosting in the building's Gothic spires. The mice, however, don't seem to be deterred.