The red carpet was rolled out this evening as former housemates were welcomed back into the Big Brother house as part of a controversial project launched by the National Trust.

Celebrity guests were treated to a champagne reception at the custom-built house at Elstree Studios, Borehamwood, which the trust plans to open up to the public this weekend.

See a gallery of photos from the evening here.

Six hundred people will have the chance to sit in the diary room chair, explore the secret safe house and climb into the treehouse.

Ivo Dawney, London director of the National Trust, told the Borehamwood Times how he dreamt the up idea a year ago, hoping to spark debate about “what is heritage”.

He said: “Nobody has difficulty thinking of big aristocratic houses in the country as being part of our heritage but we want people to think more broadly about what heritage is.

“There’s been a lot of criticism saying this project is all about celebrity culture but in a way it is like that – we do have a celebrity culture in the UK.

“And, I think Borehamwood and Elstree should be very proud of being part of that modern Britain.”

Among the line-up of tonight's celebrity guests were supermodel Sophie Anderton and her former housemate Lauren Harries, who came third in the last season of Celebrity Big Brother.

Lauren said: “Big Brother changes your life and your perspective on life – you don’t have phones or contact with the outside world or television.

"It makes you realise how wonderful it can be in the outside world. That’s what the Big Brother experience is all about. I think it’s great people have the chance to come and see where that takes place.”

Former Big Brother contestants Dexter Koh and Liam McGough also backed the controversial scheme, while admitting it was a chance for them to “get closure” on their own personal experiences in the house.

Twenty-nine-year-old Liam who has gone on to run Liam McGough’s Tree Services in north London, said: “When we were driving here in the car I had a bit of anxiety. When you leave you still feel like Big Brother has a bit of a hold on you like you’ve lived in it’s womb.

“It’s great to be able to come back - even the smell of the place is remnant of an important time in my life.

“I think it’s good the National Trust is trying to get people interested in heritage as well. This is probably the most famous house in the country for right or wrong reasons.”

While Dexter said: “I travelled all the way from Liverpool because I wanted to come and show my support.

“This house is about heritage because British society is raised and born on television. Our culture today is based a lot on what we see on television and people are often learning more on television than what they learn in class.”

The Big Brother house will open to the public this Friday and Saturday although tickets must be bought in advance via www.nationaltrust.org.uk/london