Nicola Sturgeon has pledged to fight the UK Government’s legislative proposals for minimum service levels during industrial action “every step of the way”.
Under the plans, minimum safety levels would be introduced to ensure vital public services – including fire, ambulance and rail – maintain a “basic function” when workers go on strike.
But the proposals from Business Secretary Grant Shapps have been branded an “attack on workers’ rights” by the SNP.
Unions have also condemned the legislative plans as unworkable and illegal.
The Strikes (Minimum Service Levels) Bill would apply across the whole of the UK as employment law is a reserved to Westminster.
It comes as school staff walk out over a pay dispute in Scotland, while in England and Wales around 25,000 ambulance workers are due to go on strike on Wednesday.
Mr Shapps said the strikes underlined the need for the legislation.
However, Scotland’s First Minister has said her party and government will oppose the “anti-trade union” legislation at both Westminster and Holyrood.
Transport Minister Jenny Gilruth had previously urged UK ministers to exclude Scotland from the proposals – a view now echoed by Ms Sturgeon.
Despite services in Scotland also being disrupted by strikes, Ms Sturgeon said negotiations are the only suitable way to avoid walk outs.
She said: “Unfortunately, employment law is reserved to Westminster but I don’t believe that should be the case. I think it should be the responsibility of Holyrood.
“I oppose that legislation. I believe that while I don’t want to see workers having to take strike action, the right to strike is a fundamental right in a democracy.
“And the way you resolve industrial disputes is by negotiations, not by legislating to take away workers’ rights.
“This is a Conservative government that has proven itself in the past to be no friend of workers and to be willing to take away workers’ rights.
“The SNP both at Holyrood and Westminster will oppose this anti-trade union, anti-worker legislation every step of the way.”
Earlier this week, Stephen Flynn, the SNP’s Westminster leader, urged Labour leader Sir Keir Starmer to work with his party to defeat the legislation.