ED Miliband has been ridiculed and likened to Moses by his political opponents after unveiling an eight-feet high stone slab bearing Labour's key manifesto pledges, which the party leader wants to install in the Downing St garden if he wins power.

On the campaign trail in Nuneaton, David Cameron mocked the "tombstone", saying: "If you have got a problem with judgement, I don't think that's going to help."

London Mayor Boris Johnson chipped in on what has already been dubbed "Stonegate", saying: "It's absolutely crazy. You've already got the Labour leader commissioning great stones that are going to be engraved like the commandments of Moses or Hammurabi or something with what he wants to do."

Chancellor George Osborne recalled Neil Kinnock's 1992 campaign as Labour leader, tweeting: "Carving stone monument for Downing Street garden looks like a Sheffield Rally moment. Once again, Ed Miliband's judgment not rock solid."

Unveiling the stone slab, Mr Miliband said: "These six pledges are now carved in stone. They are carved in stone because they won't be abandoned after the General Election.

"I want the British people to remember these pledges to remind us of these pledges, to insist on these pledges, because I want the British people to be in no doubt, we will deliver them."

Later, he denied the slab was "naff" and added: "I'm going to leave the landscape gardening part of this to other people. I don't measure the curtains or the garden."

Meantime, Chris Leslie, the Shadow Treasury Chief Secretary, was asked if Labour had planning permission to erect the slab in No 10's rose garden. He replied: "Oh for goodness sake. If that's what the election is hanging on...we'll make sure we abide by all the regulations that are there."