WALES (TIP):Scotland and Wales are in preliminary talks to split away from the UK and form a new country if Britain votes to leave the European Union in June.

The extraordinary proposal has been discussed by members of the Welsh Assembly and Scottish Government, and it is being taken seriously by the UK Government.

The Independent can reveal the plans today after it was passed redacted documents by a Cabinet Office whistle-blower.

Under discussion are designs for a bridge or tunnel linking the two countries directly via the Isle of Mann, with the “Celtic Union” among a number of name suggestions that would ultimately be decided at a second referendum.

Dubbed a “joint cessation”, the plans come amid concerns among Welsh and Scottish leaders that they will be pulled out of the EU against the wishes of their people.

Downing Street has tasked civil servants with compiling a list of the most dramatic possible outcomes in the event of a British exit.

Documents leaked from the resulting Cabinet Office committee meeting on “Brexit consequences” suggest David Cameron’s senior advisors are aware of the ongoing behind-the-scenes talks.

The files include redacted minutes from meetings where the idea of the “new nation” was discussed, as well as a map drawn up by civil servants to show how a proposed direct link between Scotland and Wales would work. They suggest the project would cost around £7 billion, and could be funded at least in part by the EU.

The Government is understood to be particularly concerned at the prospect of people passing into the new union being required to use passports.

And the committee also heard from a Bank of England expert who suggested splitting the country in two would result in “a prolonged period of stagnation” for both economies.

The Independent attempted to acquire details of the proposal through a Freedom of Information request, but this was turned down by Cabinet Office officials.

Following the refusal, a set of documents was physically removed from Whitehall offices by the whistle-blower.

The Independent has agreed to protect his identity since the decision to remove official papers may have serious consequences for him. He has fled the country with the aid of transparency campaigners, and is currently safe in an undisclosed location in Moscow.

The fact that the full extent of consequences for Brexit has been kept under wraps by the Government will raise serious questions for Number 10.

Despite redactions it seems clear the committee, which has met at least three times in the past month, was preparing to brief ministers about secretive discussions between Welsh Assembly members and MSPs.

The Scottish National Party has already indicated that a vote to leave the EU would reignite the independence question, assuming that a majority of Scotland’s population votes to remain inside the EU. It is now apparent that Welsh Assembly members are considering similar moves.

One member is minuted as querying whether cessation by Scotland and Wales would require a name change for the UK, left as an English and Northern Irish rump, including the idea of dropping the “Great” from Great Britain. It is unclear whether Northern Ireland’s Assembly at Stormont has been party to the Scottish and Welsh negotiations.