NICOLA Sturgeon’s government has “gone awfully quiet on the independence front since the election”, an SNP MP has said in a demand for more details by the autumn.

Joanna Cherry QC also described the modest increase in support for independence since the referendum of 2014 as "poor" given Brexit and Boris Johnson.

She said there was a pressing need for a new independence prospectus dealing with the economy, trade with the rest of the UK and rejoining the EU.

The party’s leaders were “not yet sufficiently well-equipped” to answer questions on those subjects, she said.

During the recent Holyrood election, Ms Sturgeon failed to explain how a trade border with England would work in light of Brexit, but insisted all would be well in the end.

Ms Cherry said: “The reality which must be recognised is that support for independence has fallen back from a high watermark of 58 per cent to about 50%. 

“A net increase of 5% in support  for independence is a poor return for the last seven years.” 

The Edinburgh South West MP made the comments in a column in the Herald’s sister paper, the National.

Many of her remarks chime with those of her political mentor, Alex Salmond, who has also called for an updated blueprint for independence as leader of the Alba party.

Raising the dearth of thinktanks generating policy ideas in Scotland, Ms Cherry said new thinking on economics, trade and the EU was “pivotal” to the Yes movement.

She said: “Along with others, I have repeatedly emphasised that Scotland needs a new prospectus for independence. 

“The three questions we need most to focus on are the economic prospectus, our trading relationship with the rest of the UK post-Brexit and the route to accession to the EU. 

“These are the questions which repeatedly come up on the doorstep, which are repeatedly put to our leaders and spokespersons and which they are not yet sufficiently well-equipped to answer satisfactorily.”

Ms Cherry also raised SNP Constitution Secretary Angus Robertson, with whom she had a notoriously bitter fight over the SNP Holyrood candidacy in Edinburgh Central.

She said: “The Scottish Government was elected with a mandate to deliver  not just a second independence referendum but independence itself. Ultimately a heavy weight of responsibility lies on those who hold the brief for the constitution. 

“I am sure they are mindful of the need to have the arguments required to persuade those not yet convinced  of the case for independence. 

“The reality which must be recognised is that support for independence has fallen back from a high watermark of 58% to about 50%. 

“A net increase of 5% in support  for independence is a poor return  for the last seven years, which have  seen three Tory governments elected, Brexit delivered in the face of  overwhelming resistance in Scotland and the rebarbative Boris Johnson become Prime Minister.  But all is not lost. 

“I have no doubt that with a lucid new prospectus for independence and a plan for the transition to statehood we could surpass 60% support for independence and build on that to a firm victory in a second vote.”

She went on: “Prior to the Covid pandemic, on Brexit Day on January 31, 2020, Scottish Government policy papers on some of the issues I have identified were promised. 

“Understandably, these were put on pause during the pandemic, but, as we move forward and recover from the pandemic, I would expect this work to have resumed, particularly given that the UK Government is steaming ahead with its constitutional agenda.

“The announcement that a new council has been tasked with drawing up a 10-year national strategy for the “economic transformation” of Scotland does rather beg the question of where independence sits in this plan. Some clarity on this is needed. 

“As others have commented, things have gone awfully quiet on the independence front since the election. 

“That does not mean there is no activity, but I would expect the Scottish Parliament to be favoured with a detailed update on this work in the autumn.”

The council Ms Cherry referred to was announced last week by SNP finance secretary Kate Forbes and includes an arch sceptic of independence, the former Treasury permanent secretary Sir Nick Macpherson.

In 2014 he advised Tory Chancellor George Osborne not to let an independent Scotland share the pound in a currency union, severely damaging the Yes campaign.

Ms Sturgeon has said she wants a second referendum by 2024, Covid permittting, with independence in 2016 if there is a yes vote.

However Mr Johnson has refused to grant Holyrood the required powers, saying the immediate focus should be on the economic recovery from the pandemic.