Nicola Sturgeon has warned that a strengthened Conservative government at Westminster would try to "crush dissent, silence opposition and steamroller" Scotland.

The SNP leader cast both the local and general elections north of the border as a battle between her party and the Tories as she launched the party's council manifesto in Edinburgh.

She stopped short of ruling out council coalitions between the two parties, although she judged the move as "highly unlikely".

With Labour lagging far behind the Conservatives in UK-wide polling, Ms Sturgeon conceded it was likely Theresa May would return to Downing Street after the June 8 snap election.

"I don't want to see a Tory government but I can read the opinion polls as well as anybody else can," she said.

"If Scotland doesn't want a Tory government that has a massive majority, that has the ability to do whatever it wants, to silence Scotland's voice, to impose cuts, further austerity, and to try to almost silence the Scottish Parliament, there needs to be really strong opposition from Scotland to that Tory government.

"That can only come from the SNP. That's the clear message that we'll be taking to every part of Scotland."

The Tories in Scotland are expected to focus on attracting support from unionist voters and those opposed to a second independence referendum by making the issue a focus of their campaign.

The SNP won 56 out of 59 seats at the 2015 general election and faces a difficult fight to hold onto the record number.

While Ms Sturgeon has said she already has a mandate for a second ballot on independence after winning the Scottish elections in 2016, success in the general election would "reinforce" it.

"The general election is about making sure that the Tories don't get to crush dissent and silence opposition, and steamroller over Scotland, how Scotland has voted and how the Scottish Parliament has voted," she said.

"It is about making sure Scotland's voice is heard and independence is certainly an aspect of that, but it's bigger than that as well.

"It is about making sure we don't allow the Tories to do the social and economic damage to Scotland that they have done in recent years."

The SNP leader also focused on an anti-Tory message for the local elections, which will take place on May 4.

"There is a danger, either through people voting Tory or Labour potentially looking at coalitions with the Tories to keep them in power, that we see local services slipping into Tory hands and I think that would be disastrous for the services that local councils are responsible for," she said.

"So, my message is a very clear, straight message - if you want to protect local services, then vote SNP."

Pressed on whether she would forbid SNP council groups from forming coalitions with Tory groups, she said: "I don't want to see the Tories in council chambers. I don't want to see the Tories with their hands on local services.

"Anybody who looks at the relationships between the SNP and the Tories right now would think that is hugely unlikely."