The ComRes poll of more than 2,000 voters put UKIP on 38 per cent across the UK, ahead of Labour on 27 per cent and the Tories on 18 per cent.
The eurosceptic party only polls six per cent in the Scottish sample.
Senior SNP sources said the poll “shows the growing political divide between Scotland and the UK”.
It comes as Ukip leader Nigel Farage has ruled himself out of standing in Newark in the East Midlands in England, the seat vacated by former Tory MP Patrick Mercer who resigned after being suspended from the Commons for six months for taking cash to ask questions on Fiji.
Asked on Sky News if he had “bottled it”, Mr Farage initially said: “Yes. At 7.30pm last night I found out there was going to be a by-election in Newark and, 12 hours later, I’ve thought hard about it overnight, and I have realised we are just over three weeks away from a European election. I’m touring around Britain, I’m trying to get people to vote for a political party that says we shouldn’t have an open door to the whole of eastern and southern Europe, we should get back the ability to govern our own country, and I don’t want to do anything that deflects or distracts away from that message.”
Pressed on whether he admitted bottling the decision Mr Farage said: “I have said absolutely nothing of the kind.”
The rise in Ukip support looks set to dent any hopes the Tories have of winning the next general election in 2015.
A survey by Survation for the Huffington Post website also suggested that more than one in three people who voted Conservative at the 2010 election would switch to Ukip if Mr Farage was to stand in their constituency.
It found that overall support among voters for Mr Farage as their local MP was 21 per cent - with 49 per cent opposed.
That included 34.5 per cent of 2010 Tory voters, 17 per cent of Liberal Democrats and 15 per cent Labour.
Survation polled 1,000 voters. SEE ALSO