The environment, education and Scotland's devolved powers are among the topics political leaders will be highlighting on the first weekend on the Holyrood election campaign trail.

The SNP, Conservatives and Greens will focus their main vote-winning efforts on Glasgow, while Labour and the Liberal Democrats will be promoting their key messages on the other side of the country.

Scottish Liberal Democrat leader Willie Rennie will put the environment at the top of the agenda when he visits Deep Sea World in North Queensferry, Fife.

He is expected to challenge the SNP to reverse plans to slash air passenger duty and invest to meet Scotland's climate change targets. Mr Rennie said: "This is no time for timidity on the environment.

"Tories in Westminster have slashed green budgets and the SNP are taking their marching orders from the airlines on an air passenger duty cut that would mean big increases in emissions."

Labour's shadow Scottish secretary Ian Murray is arguing that his party will invest in education and not cut vital staff.

He has claimed that nearly 1,000 jobs have gone from Scotland's primary schools since 2013, including more than 800 additional support needs workers and nearly 90 nursery nurses.

Mr Murray, who will be on the campaign trail in Edinburgh, said: "Education is the single most important economic investment a government can make, we should be investing in these jobs, not scrapping them.

"That's why Scottish Labour would introduce a 50p tax rate for the richest 1% in our country and invest it in schools."

First Minister Nicola Sturgeon will campaign in Pollok with local candidate Humza Yousaf.

The SNP leader will visit the Village Storytelling Centre in the constituency and lead a storytelling session with local children.

She will say: "A re-elected SNP government will not just protect the gains of devolution, we will use our new powers to go further, ensuring taxpayers across Scotland receive the benefit of their contribution to Scotland's future."

Scottish Conservative leader Ruth Davidson will make a speech in Glasgow on Saturday, while Scottish Greens co-convener Patrick Harvie will also join campaigners in the city.

Ruth Davidson will say: "We saw what will happen from Thursday night's debate - we will end up with a high tax First Minister being told by a high tax Opposition leader that taxes aren't high enough.

"And that's why we're needed. Because it is only us, the Scottish Conservatives, which can stop that escalator in its tracks."