SNP MSPs have been given a deadline of the beginning of next month to tell party headquarters if they don’t want to fight the Scottish Parliament election next year, The National can reveal.

The date of March 6 has been set as the party step up preparations for the poll regarded as of historic significance in the independence campaign. Letters were received by MSPs from party officials last week.

Kirsten Oswald MP, the SNP’s business convener, said: “Following the SNP annual conference’s decision on extending the use of all-women shortlists to increase female representation towards our 50/50 target, we are asking those MSPs who are not seeking re-selection to inform the NEC. This enables the necessary action on the use of all-women processes in individual constituencies to be taken.

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“The SNP are proud of our record in delivering gender balance, with this positive action and Nicola Sturgeon, the first female First Minister, appointing Scotland’s first-ever gender-balanced Cabinet.”

The National: Nicola Sturgeon

The SNP and the Scottish Greens want to secure a pro-independence majority in May 2021 to heap more pressure on UK Prime Minister Boris Johnson to grant Holyrood the powers to hold a new plebiscite.

A fourth term in government would further strengthen the party’s mandate for a second referendum, with

even pro-UK Scottish Labour leader Richard Leonard conceding a Holyrood pro-independence majority would make it democratically difficult for the Conservative Government to continue to oppose a second ballot on Scotland’s constitutional future.

But it is also being seen as a way to bring new talent into the parliamentary group, refresh the Cabinet and allow the First Minister to line up a possible successor for whenever she decides to stand down, which could be following the 2026 elections.

Sturgeon is to reshuffle her top team following the shock resignation of finance secretary Derek Mackay after revelations over him sending messages to a 16-year-old boy.

There is speculation that Kate Forbes, the Public Finance Minister, who was widely praised for delivering the Scottish Budget on Thursday at short notice, might be given the role.

However, some believe there could be a wider reshuffle with deputy First Minister and Education Secretary John Swinney stepping into the finance role, with education going to another frontbencher.

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There is concern too – echoed by Sir John Curtice, professor of politics at Strathclyde University, in The National earlier this week – that the First Minister needs to review her leadership style and adopt a less “presidential” style. The source added: “It’s usual that first ministers carry out a reshuffle about a year before an election, so one is on the cards regardless of the events of this week. A more collegiate Cabinet would be good, there is a general feeling about that.

“Nicola, in my view, needs to strengthen the Cabinet. I think there is a feeling we have lost momentum. I think we need a combination of experience and new blood in government both ahead of the election and also over the longer term.

“And perhaps those who are not performing so well should be given other opportunities.”

It’s not yet known which politicians would be considering stepping down and whether any of the intake from the first reconvened Scottish Parliament in 1999 are considering drawing their parliamentary career to a close. There is no requirement to retire at a particular age and many Westminster parliamentarians work on into their 70s.

A number of senior figures in the party who don’t have Scottish Parliament seats are believed to be considering standing for Holyrood. Angus Robertson, the former SNP deputy leader, Joanna Cherry, the Edinburgh South West MP and Alyn Smith, the Stirling MP, are being discussed as a possible hopefuls. All three would be regarded as potential ministers and even future leadership contenders.