THE pro-UK parties yesterday announced they had recruited a panel of constitutional experts to come up with a single question for the independence referendum ballot paper.

The move prompted Alex Salmond, who last week appointed his own referendum adviser, to brand the tactic a "desperate and silly gimmick".

Labour, Conservatives and the Liberal Democrats said the creation of the panel would ensure a clear and neutral form of words for a straight yes/no ballot due in 2014.

It will be chaired by Lord Sutherland of Houndwood and feature Dr Matt Qvortrup, an expert on constitutional issues, and Ron Gould, who investigated the fallout from the troubled 2007 Holyrood election.

Their proposed question will be submitted to the Electoral Commission for testing; the Scottish Government has already made clear its preferred question would be tested by the elections watchdog.

Johann Lamont, the Scottish Labour leader, said: "The question to be put to the Scottish people in the referendum is too important to be left in the hands of politicians."

She made clear the offer was still on the table "for the First Minister to join with us and take this forward on a cross-party basis".

However, Mr Salmond's spokesman was scathing about the new panel, saying: "It is presumptuous in the extreme of the anti-independence parties to prejudge the referendum process by trying to narrow the options available to people in the referendum before the conclusion of the Scottish Government's consultation process.

"The referendum must be made in Scotland without any Westminster strings attached."