COMMUNICATIONS were taking place between senior Treasury officials and the Royal Bank of Scotland before an email was issued leaking sensitive information about the bank’s plans to leave the country in the event of a Yes vote.

An email trail seen by The National shows the Treasury was forwarding to RBS Better Together press releases about other businesses threatening to leave Scotland after a Yes vote. The emails were sent as RBS executives were preparing to meet to consider their own position on Wednesday, September 10 last year.

At 10.15pm that Wednesday night the Treasury issued an email to journalists stating RBS had plans to move to London in the event of independence. The email was issued before the RBS meeting had ended.

The Treasury email tells journalists: “As you would expect RBS have also been in touch with us and have similar plans [to Lloyds Banking Group] to base themselves in London.’’

But the trail seen by The National reveals that RBS did not email the Treasury until half an hour after the Treasury’s email had gone out, saying that it would announce the following day its own plans to leave an independent Scotland.

A message from RBS sent at 10.45pm to the Bank of England and John Kingman, HM Treasury’s second permanent secretary, with the subject “Indy vote” states: “(Name redacted), John, RNS tomorrow first thing confirming re-domicile intention. Board all agreed, eventually.”

In light of the revelations – and the Treasury’s link to Better Together revealed by our sister paper the Sunday Herald yesterday – the SNP’s leader at Westminster Angus Robertson has demanded that Sir Nicholas Macpherson, the Permanent Secretary to the Treasury, explain himself before a Holyrood committee.

“The Treasury cannot just change the rules governing the civil service to suit themselves,” Robertson said. “And there must an assurance that events such as these cannot happen again.”

The Treasury’s email was issued just days before the referendum vote, triggering headlines that were widely seen as a blow to the Yes campaign.

Many media reports suggested there would be substantial job losses if RBS was to leave , a suggestion denied by the bank’s chief executive officer Ross McEwan on September 11. McEwan wrote to staff to apologise for the fact that they heard the story first from the media.

But he told them the threatened move would be a “technical procedure’’ and added: “It is not our intention to move operations or jobs.’’

Treasury officials have insisted their email was only issued in response to a story in a newspaper. But the email trail seen by The National shows that John Kingman, sent an email to RBS at 1.55pm on the day of the RBS meeting on September 10 forwarding a press release from Better Together, which focused on comments from senior business figures at Standard Life and BP setting out the economic risks of separation.

Two more emails were sent by Kingman on the same day to RBS before the Treasury RBS email was issued at 10.16pm, while the RBS board meeting was ongoing. In an email sent at 7.16pm, Kingman states: “Sounds like Lloyds will put something out tonight.”

A further email sent at 8.23pm from Kingman to RBS states: “Hmmmmm – I wish them good luck with that! Just tried to call – I think (name redacted) will also speak to (name redacted).”

The latest revelations come after the Sunday Herald revealed how the Treasury civil servant who issued the email about RBS’s plans to leave the country in the event of a Yes vote had links to the head of the Better Together campaign.

Former First Minister Alex Salmond has already asked the Financial Conduct Authority (FCA) and City of London Police to take action on the Treasury email, which he argues breaks the rules on announcing financial news before the stock market has been informed. “If senior civil servants are intervening in politics you are on a slippery slope,” he said.

The FCA says it has no power to consider a criminal action against the Treasury and has ruled out a “civil’’ investigation.

City of London Police said it would take whatever action it considered appropriate.

Robertson added: “These revelations pile further pressure on the Treasury. There are now a number of serious questions to answer about its conduct during the referendum and the people of Scotland deserve the truth.

“The fact the Treasury’s meddling in the bank’s affairs led to a leak which breached financial market rules and pre-referendum guidelines is also a matter of record. The people of Scotland must know what other underhand tricks the Treasury pulled in the run-up to the referendum.

“Serious questions also remain about Sir Nicholas’ role as the independence vote approached – he has already effectively conceded that the Treasury was politicised in the run-up to the referendum. Sir Nicholas Macpherson must now come before a

Holyrood committee to explain his perspective.”

A Treasury spokesperson said: “These emails simply show that Treasury officials are in touch with a range of people in the financial services industry on a daily basis.”