The question for the independence referendum needs to be agreed by all the political parties, according to the leader of the Scottish Liberal Democrats, Willie Rennie.

Speaking in advance of the launch of the SNP's independence campaign he said:

"It's in the interest of whoever wins the referendum to have the acceptance of those who lose. A critical part of that is a fair question accepted by everyone. Yet, the SNP seem to think only they should determine the question that is asked.

"I am urging Alex Salmond to be reasonable and work with all political parties to set the independence referendum question.

"If he has confidence that he can win he should be look to build the broadest possible consensus around the process used to reach his goal.

"As it currently stands it difficult to see how there will be a consensus. People will simply conclude that he is so desperate he will do anything to win, including rigging the referendum.

"If he wants to win fairly he should agree to a cross party committee to set the question."