A free hypnosis CD is included at the back of every copy of the Labour Party election manifesto to help voters feel calm, relaxed and totally unable to remember the last 13 years.

“As people listen to my voice,” said Lord Mandelson, “they will slowly feel themselves drifting into a trance-like state of well being, safe in the knowledge that voting Labour will help them to lose weight, achieve instant confidence and become more successful than they have ever imagined.”

The CD has already been criticised by David Cameron: “Hypnotising the electorate is a cheap trick and yet another example of Labour stealing Conservative ideas. Michael Gove has produced our mind programming CD although so far it mostly sends people to sleep.”

Nick Clegg was so angry that he personally rang up Lord Mandelson to complain. However, following a short conversation, Mr Clegg reported feeling much better about himself and is now planning to vote Labour.

Experts believe that the prime minister is showing increasing signs of being under the influence of the dark Lord. “You only have to look at Gordon to see that he has been reading Mandelson’s self-help book, ‘I Can Make You Grin’,” said hypnotist, Derren Brown, “and if you slow the video footage down you can clearly see that he is sending out the subliminal message: ‘Help Me!’”

Mr Brown has rejected accusations that Lord Mandelson has become too influential. “Peter is a close personal friend of both myself and Sarah and the fact that he is the only man who can cure our children of haemophilia is neither here nor there. Besides, people have tried killing him off loads of times and he always survives.”

Speaking at a press conference Lord Mandelson denied allegations that he was also behind a nationwide campaign of subliminal adverts. “Have you seen any of these subliminal adverts?” he asked reporters, “No. Of course you haven’t.”