Finance Minister Michael Noonan has hit out at Boris Johnson's plans for the UK in Europe, saying his proposals are "contradictory".
The former London mayor has written this morning in a Daily Telegraph column that he wants to have free trade with the EU, while controlling immigration.
Stock markets across Europe have fallen today amid ongoing confusion about what Britain will ask for in its exit talks.
Michael Noonan said the precedent set by Norway is that if any country wants free trade with the EU, it will have to pay for the privilege.
"(Norway) had to pay the levies that countries pay to the European Union, and had to give free travel and free labour market movement (in return)," he said.
"So, from the precedents, it doesn’t seem (the option of free trade and simultaneous immigration control) is open to (Boris Johnson), but I can see why he's saying it even though the positions are contradictory - that's what he campaigned on."
Boris Johnson this morning declared "Project Fear over" after British Chancellor George Osborne said an emergency post-Brexit budget was unlikely to happen until a new prime minister is in place in the autumn.
The leading Leave campaigner welcomed the early morning statement by Mr Osborne intended to calm the markets that the UK economy was "about as strong as it could be" to confront the challenge of separating from the EU.
"It is clear now that Project Fear is over, there is not going to be an emergency budget, people's pensions are safe, the pound is stable, the markets are stable, I think that's all very good," he told reporters as he left his London home.