Daventry's MP left members of a Brexit committee shocked after he rejected the suggestion that 1,000 police officers were training for deployment in Northern Ireland in the event of a no-deal.
Instead, Junior Brexit minister Chris Heaton-Harris argued the officers were being readied for marching season, a time when extra officers are needed to police tensions between Protestant and Catholic communities.
Mr Heaton-Harris was being questioned by fellow MPs at an exiting the European Union committee on Wednesday.
Chair of the committee Hilary Benn, Labour MP for Leeds Central, referred to a Guardian report that stated almost 1,000 police officers from England and Scotland were to start training this month for deployment in Northern Ireland in case of disorder from a no-deal Brexit.
The potential reinforcements are considered necessary in case of civil unrest over border arrangements that could be put in place after a hard Brexit.
The officers would be pulled from their regular duties and would need specific training because some equipment and tactics used in Northern Ireland vary from those in the rest of the UK.
When quizzed about the officer training, Mr Heaton-Harris said he did not believe they were expected to do additional work in the event of a no-deal, adding that police officer numbers often increase "as you head towards marching season".
"The marching season?" said a visibly stunned Mr Benn.
"I'm sorry did you say marching season? Well, the marching season has been last year, the year before, the year before that and it's in July and I'm not aware that that resource has been called upon previously.
"My understanding from the reports I've read was that this is specifically to provide assistance in the event of no-deal. Can you confirm whether that is or is not the case?"
"I don't believe that's the case," said the Daventry MP.
An additional 1,000 officers would be roughly double the amount requested to police marching season in recent years.
Joanna Cherry, an SNP member of the committee, called the Brexit minister's answer “disgraceful”.
"A disgraceful performance so far," she tweeted.
"For example he has just claimed that extra police for Northern Ireland are 'for the marching season'."
"He’s making the fatal assumption of assuming we are as stupid and uncaring as he is."
Other points made by Mr Heaton-Harris during the meeting include his statement that there was no "parliamentary route" that would allow pro-EU MPs to stop the UK leaving the EU.
"The legislation is set out now, and the fact that we have activated Article 50, I actually still believe we will be leaving the EU on March 29 at 11pm," he said.
"Is there a parliamentary route with which Brexit can be stopped? I do not believe so."
He also said that the number of bits of secondary legislation to be passed before March 29 was now “below 600”.