The Scottish Greens are optimistic about growing the size of their group at Holyrood as the country heads to the polls this week.

Despite a new pro-independence party emerging to contest the regional lists – where the Greens usually win seats – recent opinion polls point to an increased vote share for Patrick Harvie and Lorna Slater’s party.

A Savanta ComRes poll on April 22 suggested the Greens might win eight MSPs, while Survation on April 25 suggested there could be 11 Green MSPs, as did Panelbase on April 27.

The Scottish Greens won six MSPs in 2016, though Andy Wightman’s decision to leave the party meant the group went down to five.

But polling for the Holyrood election, especially in the regional lists, can be fickle and differences of a few percentage points can result in big changes in the number of seats parties receive.

Mr Harvie launched the Greens’ campaign with the slogan “vote like our future depends on it”, stressing their environmental credentials and saying they have a track record of pushing the Scottish Government “beyond its comfort zone”.

The pro-independence party says it wants to see a second referendum within the next session of Parliament, after the pandemic.

Their campaign launched before Alex Salmond unveiled his new Alba Party, with the former first minister saying only his group can inject more urgency into the push for independence.

The SNP, which has maintained a comfortable lead in the polls, has urged its supporters not to lend their list votes to other parties, and the slogan “both votes SNP” has been a prominent part of Nicola Sturgeon’s campaign.

Pro-union parties have long accused the Greens of being an extension of the SNP, aiding the First Minister’s party in key votes.

Ms Slater appeared for the Greens during the first televised debate of the campaign, saying Scotland should not return to the “broken system” in place before the pandemic.

During the BBC debate, her first as the party’s co-leader, she said: “Around the room we hear people who are in favour of the union not actually arguing for the union, but instead arguing that the people of Scotland shouldn’t have the right to choose.”

The Greens have fielded 12 constituency candidates around Scotland as well as candidates in each regional list.

While the Greens are unlikely to pick up any constituency seats, it will be worth watching the contest involving Mr Harvie in Glasgow Kelvin.

He picked up 24% of the vote share there in 2016, finishing second, and may be able to reduce the SNP’s majority this time around.