Openly gay Conservative MP and shadow leader of the House of Commons Alan Duncan has apologised after being caught on camera complaining that MPs are now “treated like s**t”.

He was filmed campaigner Heydon Prowse, the editor of Don’t Panic magazine. He was invited by Duncan to visit parliament in June.

Duncan, a multi-millionaire, also said that MPs are forced to live on “rations” following news of grossly inflated expenses claims.

This morning, he apologised for the comments, saying they had been made as a joke.

He said: “The last thing people want to hear is an MP whingeing about his pay and conditions.

“It is a huge honour to be an MP and my remarks, although meant in jest, were completely uncalled for. I apologise for them unreservedly.”

When the expenses scandal broke, Duncan,who receives an MPs’ salary of around £65,000, was forced to apologise and pay back nearly £4,000 he claimed for gardening costs.

In the taped interview, he said: “I spend my money on my garden and claim a tiny fraction based on what is proper. And I could claim the whole bloody lot, but I don’t.”

When asked how much he spends on his garden, he said: “About £2,000 a year and this was £1,000 a year on expenses, you know. It’s just, I’m afraid the world has gone mad.”

He summarised life as an MP as: “Basically, it’s being nationalised, you have to live on rations and are treated like s**t.”