The European elections are shaping up to be a contest between the SNP's "open and friendly view of Europe" and Ukip's "anti-European agenda", according to the Nationalists' deputy leader Nicola Sturgeon.
She said the only way to stop Ukip from gaining a seat in Scotland is to vote for her party's candidates.
She was speaking at the launch of the SNP's European election manifesto, ahead of the ballot on May 22.
"I think as the campaign progresses there is absolutely no doubt that it is shaping up to be a contest between the open and friendly inclusive view of Europe that the SNP has, against the pretty miserable anti-European, anti-devolution agenda typified by Ukip," she said.
"The only way to stop Ukip getting a seat in Scotland is to vote SNP, and I think it would be very appropriate and very desirable if (SNP candidate) Tasmina Ahmed Sheikh was to be the candidate who stopped Nigel Farage getting a foothold in Scotland."
Ms Sturgeon went on to add: "You can look at the statements of Nigel Farage or other Ukip members over a long period of time that paint a picture of an anti-devolution party.
"Nigel Farage wants to try to paint out some of the rather uncomfortable remarks that are on the record, that tells us what kind of party he leads."
The last election saw the SNP win two out of Scotland's six European Parliament seats. The party has pledged to "ensure that Scotland's interests are always defended" in Europe.
Its manifesto includes promises to work with Europe to secure jobs and investment, to "stand up for our agriculture and fishing sectors" and to advance Europe's social agenda, particularly the living wage.
Speaking during a visit to Edinburgh last week, Mr Farage said his party is "on course to win one seat in the European Parliament in Scotland, and if things go really well, possibly even two".
Labour won two seats at the last election, while the Lib Dems and Conservatives got one each. Those parties, along with the Greens, launched their election campaigns earlier this month.
Maggie Chapman, the Scottish Greens' lead candidate for Europe, said: "The Green message - that we welcome those who want to live and work here, that we reject the Nato nuclear alliance, and that we champion social and economic justice - is the exact opposite of Ukip's message of hate.
"So electing the first Scottish Green MEP would send a far more distinct, positive message than simply adding a third SNP MEP."