A speech by the Prime Minister on Tuesday about Brexit may lead to Scotland having no "other option" than to hold a second independence referendum, the Scottish Greens have said.

Ross Greer MSP issued the warning to the Prime Minister before she sets out her government's plans to leave the European Union.

According to reports in several newspapers on Sunday, Theresa May is expected to leave the European single market as part of Brexit.

Greer said: "A hard Brexit will cost around 80,000 jobs and a £2000 drop in the average income in Scotland.

"The reports that Theresa May will announce such a plan show that her Westminster government couldn't care less about the best interests of those north of the border or how we actually voted.

"The angry, isolated Britain they clearly have in mind isn't something I believe most people here want to be a part of."

He added: "If these reports are true it is hard to see any other option than a referendum on Scottish independence, giving people a choice between self-government and this hard Brexit disaster-in-waiting.

"Westminster clearly isn't interested in compromise or a separate arrangement for each part of the UK which suits its interests and wishes.

"We need to put Scotland's future in Scotland's hands - it's clearly not safe with the Tories."

Votes from Green MSPs will be needed to pass any legislation for a second independence referendum as the SNP formed a minority government.

All three other opposition parties - the Scottish Conservatives, Labour and Liberal Democrats - have vowed to vote against any plans to hold a second vote.

The Scottish Conservatives said the Greens are becoming "as bad as the SNP" over Brexit.

The party's chief whip John Lamont said: "If the Greens think there's going to be another independence referendum, they'll have to provide the one million signatures they said would be required to allow one.

"They're becoming as bad as the SNP when it comes to making the Brexit rules up as they go along.

"Instead of ignoring the will of the British people, the Greens would be better helping the whole country reach a deal which benefits everyone."

The Scottish Government has put forward proposals to the UK Government to ensure Scotland remains in the single market even if the rest of the UK does not.

If the plans are rejected the Scottish Government has said independence should be an option for Scotland.

The First Minister said: "If the real and substantial risks that Brexit poses to Scotland's interests cannot be mitigated within the UK, the option of choosing a better future through independence should be open to the Scottish people. "

The Scottish Government has drafted legislation to go forward with plans for a second independence referendum.

The Scottish Parliament does not currently have the power to hold a legal referendum on the constitution without Westminster temporarily devolving the power.