THERESA May has been accused of sowing confusion over whether or not Scottish fishermen might still have to abide by the rules of the EU’s common fisheries policy once Britain enters a post-Brexit transition period.

Michael Russell, the Scottish Government’s Brexit minister, complained that it was “almost becoming a case of having to read the runes of[UK Government] statements and try to work out what they mean”.

During PMQs, Mrs May was asked by Alistair Carmichael, the Liberal Democrat Chief Whip: "When we have left the European Union, we will be leaving the common fisheries policy?”

The Prime Minister replied: "As part of the agreement that we need to enter into for the implementation period, obviously this and other issues will be part of that agreement. But when we leave the European Union, we will leave the common fisheries policy."

On Monday, Mrs May in a Commons statement made clear that as Britain left the EU, it would leave “full membership” of the single market and the customs union. But she also stressed that an agreement for the two-year implementation period should mean Britain operating “on the same basis and on the same rules and regulations”.

Michael Gove, the Environment Secretary, is said to be pushing for the UK to leave the CFP immediately after Brexit and not remain in it through any transition/implementation period.

But Mr Carmichael said: “The question that I put to the Prime Minister could not have been more straightforward; unfortunately, the same could not be said for her answer.

“Once we leave the EU we shall no longer have a seat at the table when the December Fisheries Council sets allowable catches and quotas for the following year. It is simply unacceptable that our fishermen should be left having to work to rules under which they have no say.”

The MP for Orkney and Shetland added: “I said many times during the recent General Election that I wanted to see fishing ring-fenced in the negotiations. This shows the importance of that approach. The Conservatives regarded the fishing industry as expendable 40 years ago. I fear that they may not have learned much since.”

Mr Russell, appearing before the Commons Scottish Affairs Committee, was told of Mrs May’s statement on the CFP and said she appeared to have confirmed that the UK would, in the transition period, be operating under an “EEA-type arrangement not a single market within the EU-type arrangement, which is another policy. There is a baffling number of policies the PM comes up with every day”.

Later he noted: “If we are out of the CFP, then there are a whole set of arrangements that need to be put in place in the next 18 months but that’s new. Transition was taken to mean transition in all these things.”

He added: “This is almost becoming having to read the runes of statements and try to work out what they mean.

“If you were a farmer of fishermen today and you witnessed that, you would ask: ‘What the hell is going on?’ What are we going to be doing in 18 months’ time?”