Pigeons have taken up residence on the rooftops at Holyrood

Some MSPs have complained that droppings and feathers have landed on their desks after getting through window and air vents.

Some windows have been sealed up to prevent the problem.

However, independent MSP Margo MacDonald, has complained that this only leads to offices overheating.

Ms MacDonald, who has been a fierce critic of the �431m building project, said: "Pigeon poo is very unsightly and it's causing a bit of a niff in some parts of the building.

"It's totally unhygienic and it's attracting flies and bluebottles."

The MSP said her secretary has had to clean her desk every day.

'Health hazard'

"This means we have to block the air vents but if we do that, the air cooling system grinds to a halt," said Ms MacDonald.

"It makes working conditions very stuffy and hot and it may be the case that the Health and Safety Executive will have to come in if the temperature is deemed to be unreasonable."

Her office manager, Peter Warren, said: "The MSP block is a metallic building with a number of ledges and recessed areas. They are the perfect place for pigeons to roost.

"But they are also part of the building's air management system to regulate the temperature.

"The parliament has only been open six months but we have had to disable some windows because when they are open, feathers and bird poo fly in. It's a real health hazard."

Officials are understood to be considering measures including fencing to deter the birds and have commissioned a survey.