The house is being built outside the Scottish Parliament

Shelter is staging the demonstration in Edinburgh in support of its plea for 30,000 affordable homes for rent in Scotland over three years.

MSPs were invited to support the call by placing one of the final 128 bricks on the house.

They have been signing a brick each before attaching it to the house.

One campaigner, Angela, who was homeless for two years with three children to look after, said being without a home of her own was a dreadful experience which no one should have to suffer.

She said: "I was living with three children in a one bedroom house, which had doors falling off and household beetles.

"It makes me sad that humans are still being treated like this. A home isn't just about bricks and mortar, its about a lot more than that."

The event comes ahead of the first ever SNP-led Scottish Executive debate on housing on Thursday, when it is hoped the SNP will outline their plans for housing in Scotland.

Ross Finnie adds a brick to the house

Archie Stoddart, director of Shelter Scotland, said: "It's time for all politicians to show they are serious about ensuring everyone can have a home.

"With hundreds of thousands of people on waiting lists, or in temporary accommodation, and rising house prices leaving many unable to buy a house, we need to give people real choices.

"This year's spending review presents us with the best chance yet to give everyone a home."

Scottish Liberal Democrat health spokesman Ross Finnie, as he added his brick to the temporary house, said: "As a party we are very concerned at the lack of affordable housing.