FOUR Liberal Democrats face a huge electoral battle to save their Westminster seats in Scotland because of the party's strong association with the Conservatives in the Coalition Government, senior party sources have warned.

Jo Swinson, Alan Reid, Sir Robert Smith and Mike Crockart will be defending majorities of less than 4000 in the 2015 General Election.

While Nick Clegg is confident the party can overcome the challenge of convincing Scots of the policy distinctions between LibDems and Tories, the LibDems nonetheless recognise the hurdle is higher north of the Border because anti-Conservative sentiment is more ingrained here.

A source close to the LibDem leader said: "It's doable but it will be extremely difficult. It's going to be one of, if not the, toughest challenge for us."

Ms Swinson has the smallest majority at just over 2000, but it is thought her role as a Business Minister will have raised her profile and helped to consolidate her position. The biggest worry appears to be over Mike Crockart, who became an MP in 2010.

Many students live in his Edinburgh consitutency. They may still be fuming over the party's U-turn on tuition fees, which the LibDems' opponents will raise in the 2015 General Election campaign.

The party as a whole will be concentrating its electoral resources on the 55 MPs it currently has in a "consolidation strategy".

Its main electoral pitch will be that the LibDems have been a "civilising force" on the Tories and have proved that coalition politics works. However, a poll this week suggested most people would, in 2015, prefer a single party to govern.

To create a clear divide between LibDems and Tories, Mr Clegg and his colleagues will use their annual conference next month to map out a "differentation" policy, particularly in Scotland.

The choice of Glasgow as the conference venue is seen by some in the party as recognising that the battle in Scotland will be tougher than anywhere else.

One party source said: "It might just have been Glasgow was the cheapest option but it will give us the chance to put a distinctively Scottish gloss not only on the … General Election but also focus on the independence debate.

"Glasgow will mark the start of an 18-month differentiation campaign. It's going to be tough in Scotland but we're optimistic with the calibre of MPs we have got, that we can maintain our strong presence there."

One ministerial source insisted that, while the General Election campaign would be tough in Scotland, the picture was not as simple as some suggest. He noted that while there was a gut political instinct against the Tories across most of Scotland, a number of Conservative supporters opted to vote Liberal Democrat instead.

He said: "We have fantastic MPs in Scotland and are confident that we can hang on to our seats. We're not complacent but we believe our approach of highlighting our distinctive policies such as taking low and middle earners out of income tax will produce results."

A weekend poll underscored the party's problem in Scotland: just 4% of voters plan to back the LibDems in consitutency and regional votes.