Brexit agreement 'impossible' within two-year period allowed by EU's founding treaty, says Irish PM

Enda Kenny says ministers will encounter 'unforseen issues' while trying to withdraw from EU

Enda Kenny says the prospect of a referendum on Irish unity should be raised by Brexit negotiators (Getty Images)

It will be "impossible" for the UK to strike a full deal on Brexit in the two-year negotiation period allowed by the EU's founding treaty, Ireland's Prime Minister has said.

Enda Kenny told Sky News the transition deal is likely to take “longer than expected” as ministers encounter "unforseen issues".

The Lisbon Treaty states that members must withdraw from the EU two years after triggering Article 50 and notifying the bloc of their intention.

But the period can be extended if the European Council unanimously decides to allow the UK longer for negotiations.

Mr Kenny said there was no evidence of a coherent plan for Brexit from Theresa May's government, after Downing Street distanced itself from a consultant's report warning that thousands more civil servants were needed for the huge workload generated by the UK's vote to leave the EU.

The report by Deloitte, dated 7 November and entitled Brexit Update, said that while each Whitehall department has developed Brexit plans, these fall “considerably short” of a Government plan because of the lack of prioritisation and an overall negotiation strategy.

It criticised Mrs May for “drawing in decisions and details to settle matters herself” and warned that big companies will “point a gun at the Government's head” after Nissan was given assurances about trading conditions once Britain leaves the EU.

A fresh row was generated following Philip Hammond's bleak Autumn Statement earlier this week, when the referendum vote was blamed for worsening national debt and plummeting growth in the economy.

Arguments are also raging within the Tory party, with pro-Brexit MPs rounding on Sir John Major on Friday after the former Prime Minister warned the terms of the UK's withdrawal from the European Union must not be dictated by the “tyranny of the majority”.

European leaders have continued to raise objection to the UK dictating favourable terms for its departure. The Maltese Prime Minister Joseph Muscat - whose country takes over the EU presidency in January - said the other 27 member states were adamant Britain could not remain in the EU single market unless it continues to accept free movement of labour.

“All of us have been pretty clear in our approach that we want a fair deal for the UK but that kind of fair deal can't translate itself into a superior deal,” he told the BBC.

“I know that there is absolutely no bluffing from the European side, at least in the council meetings I have attended, saying 'We will start in this position and then we will soften up'. No, this is really and truly our position.”

Responding to his comments, a Downing Street spokesperson said: “This is a negotiation that will take place next year and the Government will set out its negotiating strategy in the fullness of time.

“The aim of that negotiation is to get the best possible deal for Britain, for British companies to access and work with and within the single market and for European businesses to have the same access here.”