By Patrick Graham and Belinda Goldsmith
LONDON (Reuters) - The struggling campaign for Scottish independence could get a lift from an expected swing to an anti-EU party in Britain's European parliament elections in May, the leader of Scotland's Green Party said on Thursday.
With eight months until a September 18 referendum, opinion polls show about half of Scots oppose ending the 307-year-old union with England, about a third favor the Scottish National Party's bid for independence and around 15 percent are undecided.
The mood could shift in favor of independence if the UK Independence Party (UKIP) does very well in the European Parliament election, Green Party leader Patrick Harvie told Reuters in an interview.
"That kind of hard right slant is quite alien to Scottish politics," Harvie, 40, one of the two Greens in Edinburgh's 129-member parliament who both back independence, said.
"It may be at that point that some undecided voters start to see the positive case for taking responsibility for our own decisions."
A poll on Thursday showed UKIP set to come second in the EU elections behind the opposition Labour party, beating into third place the Conservative Party of Prime Minister David Cameron, who opposes Scottish independence.
Harvie, an increasingly prominent figure in Scottish politics, said he would not want to bet on the result of the referendum
Scotland's Greens are campaigning for greater use of renewable energy in a country that is a pioneer of wind and wave power as well as having offshore oil reserves. While the Greens back the SNP on independence, on many issues they appeal to left-leaning supporters of Labour, the main opposition in Scotland's parliament.
The Labour Party is trying to come up with plans for constitutional change that would keep Scotland within the United Kingdom but shift more powers from London - something polls show most Scots would favor.
Harvie said he saw the potential for the Labour party to split on the extent of those proposals after its Scottish conference in March, potentially aiding the pro-independence camp.
"If people in the Labour Party start to peel away then that could change the dynamic far more powerfully than anything we've seen to date," he said.
Campaigners against Scottish independence say it would be unrealistic, costly and unworkable.
A 'Yes' vote would certainly open a can of worms financially, including negotiations with London on dividing up debt, oil revenues and the operations of two of Britain's biggest banks.
Harvie is among Scottish politicians, including some in the SNP, who have spoken in favor of at least preparing the ground for dropping sterling and creating a new independent currency. SNP leader Alex Salmond has said an independent Scotland would want to keep the pound, at least for a time.
Defending the idea of a new currency, Harvie said "In the longer run, and it might be over a number of years, the economic needs of Scotland and the rest of the UK would be more likely to diverge."
(Editing by Matthew Tostevin)