THE Assembly Rooms in Edinburgh is a good venue for a conference. Or, to be specific, it's good venue for a small conference. The Georgian splendour – all that gilt cornicing and those classical proportions – lends a definite sense of style.

But step away from the main hall and the modest scale of the Scottish Liberal Democrats' get-together, which continues here today, is all too plain.

Only a dozen or so organisations – charities, trade unions and the like – have set up stall on the conference fringe. The way the stands skirt the room gives the conference the look of a village fete, albeit an upmarket one with chandeliers.

The gaggle of activists milling about at the start of proceedings might have been waiting for a sedate ceilidh.

Less than a decade ago, the LibDems were running Scotland in coalition with Labour. Today, after five years of coalition government at Westminster with the Conservatives, they are rock bottom in the polls.

The latest Holyrood poll, by Survation for the Daily Record, put support for the Scottish LibDems on six per cent, down one point from the same company's previous survey.

That left them trailing the Greens and even Ukip in the all-importantly battle for regional seats.

No-one at the Assembly Rooms this weekend is predicting anything other than a very tough election.

Senior LibDems are realistic: most accept that holding the five Holyrood seats they took in 2011 (down from 16 in the previous 2007 election) would not be a bad result.

But they are not completely downhearted.

They insist there is a chance of adding to their tally of MSPs and, regardless of the voters' eventual verdict, believe they have a strong message to get across before people go to the polls on May 5.

Disillusionment at Nick Clegg's coalition with David Cameron is "more muted but obviously still a factor," one senior party figure told me.

"Our task now is to convince people we have something positive to say and a contribution to make," he went on.

"All the polls suggest the SNP is going to have another outright majority after the election.

"Perhaps this is an election in which voters are being asked how they want a government like that held to account.

"It sure as hell won't be held to account by its own backbenchers, we know that.

"Five LibDem MSPs have held the SNP's feet to the fire on more issues and more consistently than Labour or the Tories."

In the weeks ahead, party strategists will make much of the LibDems' record in opposition, where their MSPs have punched above their weight, as leader Willie Rennie claimed fairly in his keynote conference speech.

In particular, the LibDems have challenged ministers effectively over the series of controversies that have engulfed Police Scotland.

They opposed the merger of Scotland's eight forces from the start, seeing it as part of an anti-democratic agenda of centralisation by the SNP.

In similar vein, they will use the election campaign to oppose the council tax freeze and restore decision-making to local authorities.

Their big policy platform, however, will be their 1p rise in income tax to invest in education, an area they claim will inevitably be hit by cuts to council budgets.

"On the face of it, increasing income tax might look unpopular," a source said. "But people, even those on lower incomes, would prefer to see jobs and public services protected.

"If we talk about using the progressive powers of income tax to make a clear investment in education we have a strong argument.

"It's about doing the right thing, rather than reinforcing the SNP's message that Holyrood is powerless to plot a different course from Westminster."

Traditionally, the LibDems have fared better when people think they can win, either with individual candidates on the ground or by holding the balance of power.

That doesn't augur well for this election.

They are quietly confident of holding their two constituencies, Orkney and Shetland, and returning regional members where they have one already: Mid Scotland and Fife, North East Scotland and the South of Scotland. Their best chance of adding to that is in Edinburgh Western or the Lothians region.

But will there be a "#LibDemFightback," to quote the conference slogan? It sounds a little too optimistic.