David Cameron has accused Alex Salmond of being "chicken" for wanting to hold a referendum on Scottish Independence in 2014 rather than in 2013.
Speaking in Troon on Friday morning, the prime minister challenged the Scottish first minister to hold the ballot as soon as possible.
"He won that election. He got the mandate. I offered him his referendum and now he won’t take it," he said.
"What on earth is going on? First he wanted a referendum in 2010 – now they say they need 1000 days. First he said they wanted one question – now he’s flirting with two.
"Now he’s talking about Devo-Max, or Devo-Plus. Soon it’ll be Devo: the sequel.
He added: "I thought we were meant to be watching Braveheart, it turns out it's Chicken Run."
Cameron told an audience of Scottish Conservatives that for too long the party had "shied away" from talking about Scottish independence and that "the time for the timidity is over".
"Now we are the ones on the front foot, asking for that referendum, looking for that challenge," he said.
"Delay creates uncertainty for businesses, investors, families. People need to know one way or the other. So my message to the First Minister is this: stop dithering and start delivering."
He added: "Let's give the Scottish people the chance to make a clear choice about their future."
The Scottish National Party administration has put forward plans for a ballot on independence in the autumn of 2014, but UK government ministers have repeatedly called for the vote to be held sooner rather than later.
The prime minister was attempting to rally his party in Scotland, which now only sends one MP to Westminster, Scottish Office minister David Mundell.
Cameron said the government has already delivered on devolution, with new powers coming to Holyrood now the two administrations have both agreed to back the Scotland Bill.