Voters seeking to "stop the SNP" can help the Liberal Democrats do "exceptionally well" in the General Election, the party's Scottish leader has said.

Willie Rennie insisted that people would vote "intelligently" in the 11 Scottish seats the Lib Dems won in the 2010 election.

Opinion polls have suggested the Scottish Liberal Democrats are facing heavy losses on May 7, with senior figures such as former leader Charles Kennedy and Chief Secretary to the Treasury Danny Alexander among those facing defeat.

The SNP is tipped to win the Gordon constituency from them, with former first minister Alex Salmond the favourite to be the next MP for the area.

But Mr Rennie insisted that his party still had time to win people over, saying: "Voters often don't make their mind up until the very last moment."

He told BBC Radio Scotland's Good Morning Scotland programme: "There's a long way to go yet and we're getting the opportunity now to put the message across about the benefits of the Liberal Democrats in government - we've cut taxes, we've increased pensions, we've got the economy back on track, we've done things like expanding childcare and investing in the NHS, and now we want to go further."

The Scottish Liberal Democrat leader said the choice voters are facing in the general election is "quite straightforward", adding: "No one party will have a majority, so therefore we have to decide who do we want to have the biggest influence in the next parliament?

"It is a choice of veering off to the left with massive borrowing with the SNP, or veering off to the right with massive cuts with the right wings of Conservative Party, the DUP and Ukip.

"I think the alternative choice, which is what we've had in government for the last five years, is Liberal Democrats, holding the centre ground, dragging the others back when they go too far, for that moderate centre ground approach which secures economic growth and opportunity for people."

He continued: "As Scottish Liberal Democrat leader, I'll always encourage people to vote Liberal Democrat. I think we've got the best programme for the government.

"But what I think is quite clear in the 11 seats that the Liberal Democrats hold there is a clear, straight choice between the Liberal Democrats and the SNP.

"If people want that moderate centre-ground approach, economic progress combined with fairness, they choose the Lib Dems. If they want to have massive borrowing, massive debts, a burden on the future, then they can vote for the SNP. It's a straight choice in those seats.

"And people will vote intelligently in that area, that's why I'm encouraged we can do exceptionally well in this campaign. That combined powerful force of good MPs, a good record in government, and a good offer for the future, combined with recognising that we need to stop the SNP."