The Sunday Mail has become the first national newspaper to ever endorse the Scottish Greens ahead of this month's European election.

One of Scotland's best-selling Sunday titles, the paper is urging voters to "go Green" due to other parties' perceived failure to give climate change "the urgent attention it deserves".

It announced its backing for "Harvie's Army" - referring to the party's co-convener, Glasgow MSP Patrick Harvie - in a frontpage editorial.

The Sunday Mail - whose sister title The Daily Record has historically backed Labour - acknowledged it was taking a "historic step" in backing the Greens.

Its editorial said: "The Euro poll in 11 days' time has been turned into a referendum by proxy on Brexit - the identity issue which has crippled our politics for almost three years and counting.

"Meanwhile we are all faced with a genuine emergency which is, in relative terms, being ignored.

"Climate change is the biggest issue confronting our country and our planet.

"According to the Royal Society of Great Britain, the rise in CO2 in the Earth's atmosphere poses a serious threat to our existence unless urgent action."

It continues: "The Sunday Mail has a proud history in tackling prejudice and fighting for social justice - though we do value our neutrality in party politics.

"Our backing of the Green party doesn't mean we agree with them on everything - and doesn't necessarily mean we'd follow them on the Yes side of a new independence referendum.

"In this election though their manifesto and vision chimes clearly with our values and the interests of our readers."

The pro-independence Scottish Greens are hoping to elect their first MEP, with their lead candidate the party's other co-convener Maggie Chapman.

The Sunday Mail's leader column also backed a vote for the Greens to reject "sinister" parties like Ukip and Nigel Farage's Brexit party.

It comes after a UK-wide poll for the Observer put the Brexit party on 34% for the upcoming election - more than Labour and the Conservatives combined.

It said: "At the last election in 2014, Chapman was pipped by David Coburn, a Ukip politician so obnoxious that Nigel Farage wants nothing to do with him.

"What a message it would send if Scotland elected a Green MEP and rejected Farage's Brexit party, Ukip and the sinister band of vaudevillian characters who sail in both."

Welcoming the paper's support, Harvie said: "We're delighted that the Sunday Mail is backing the Scottish Greens in the European elections this year.

"This is the most important European election we've ever faced, it's vital that we elect Scotland's first Green MEP to work in tandem with our European neighbours and tackle the climate emergency."

The European election will be held on May 23, with eight parties and two independent candidates competing in Scotland.

The Scottish Greens launched their manifesto on Tuesday, while the SNP and Scottish Liberal Democrats fired the starting gun on their campaigns on Thursday.

The Scottish Conservatives, Scottish Labour and the Brexit party are due to hold events in Scotland next week.

Change UK is expected to hold a rally north of the border on the weekend before the election.