A Conservative MP has accused NI’s chief civil servant of engaging in ‘operation fear’, by warning of the impact of a no-deal Brexit.
Daniel Kawczynski is backing Boris Johnson to become the next prime minister.
The BBC has contacted the Northern Ireland Executive for a comment.
Mr Kawczynski said Mr Johnson is “committed” to leaving the EU by 31 October, even without a deal.
Mr Johnson, the frontrunner in the Tory leadership race, has said the “way to get a good deal is to prepare for no deal” and has committed to leaving on 31 October “deal or no deal”.
He has also called for the Irish border backstop to be removed from any deal and be negotiated in the next phase of talks with Brussels.
Mr Kawczynski was asked on BBC Radio Ulster’s Sunday News programme if Mr Johnson was aware of warnings by the NI Civil Service about the impact of no deal on Northern Ireland.
He replied: “That is absolutely untrue and is part of Operation Fear, designed to frighten people.
“Nobody knows exactly what will happen if there is a managed no-deal basis, they are speculating and trying to spin the situation.”
He added that the UK’s top civil servant, Sir Mark Sedwill, had recently said the UK government is in “pretty good shape” to cope with a no-deal Brexit.
However, the prime minister has previously said NI was unable to prepare fully for a no-deal Brexit, because of the collapse of devolution.
Mr Kawczynski is a former member of the European Research Group, the Eurosceptic group of Tory MPs at Westminster.
He quit in April, after becoming concerned that a “hardcore element of ‘Unicorn’ dreamers” was “endangering Brexit”, by refusing to vote for the government’s Brexit deal.
He has also criticised the DUP in the past, and accused the party of holding the government to ransom by opposing the Irish border backstop.
The DUP’s confidence-and-supply pact with the government, which gives it a majority in Parliament, is due for renewal with whoever becomes the next leader of the Conservatives.
Mr Kawczynski said if he becomes prime minister, Mr Johnson had an opportunity to win a general election to ensure the government was “not at the beck and call of the DUP”.