During his first week in office, the prime minister told the Commons that he would "unshackle" British officials stationed in Brussels "right away" to use their talents elsewhere in the world.
It comes amid reports that civil servants are to be told within days they will no longer participate in regular working groups with their counterparts from the other 27 member states.
Sir Malcolm Rifkind, the former Conservative foreign secretary, told The Independent he believed the move was part of Number 10's strategy to show the prime minister is not bluffing in his "do or die" pledge to deliver Brexit by 31 October.
Tom Tugendhat, the chair of Westminster's foreign affairs committee, also raised concerns, claiming it was "bizarre" to be opting out of bodies taking decisions that could still affect the UK after Brexit.
The Guardian reported on Monday the UK diplomats are to pull out of day-to-day EU meetings in the coming days involving issues such as security, foreign policy, and the protection of consumers interests.
Foreign secretary Dominic Raab is still expected to meet with his EU counterparts in Helsinki towards the end of August.
A government spokesperson did not deny the reports, adding: "We are leaving the EU whatever the circumstances on 31 October. It therefore makes sense to review our attendance at EU meetings to make sure we are making the best use of government time. This process is ongoing."
But speaking to The Independent, Sir Malcolm said: "I think I understand why they are doing this, but I also believe it's an unnecessary and rather self-damaging gesture.
"Of course the government is right - if the reports are correct - in saying we're going to be expecting to leave in October and therefore we don't want to devote lots of resources to committees and meetings which will not concern us in a couple of months time.
"However, it is a couple of months and we have a mission in Brussels and it shouldn't be beyond our capability to have at very least one relatively junior diplomat sitting in on the meetings if only just to find out what's going on. It's called intelligence gathering. Therefore I think this is rather ill-advised."
"Two months is quite a long time," he continued. "I don't know which committees or meetings we're talking about but if it's most of them, or all of them, then we're going to be depriving ourselves of a lot of information that we will be spending the next few years trying to find out by other means."
Mr Tugendhat also said he was concerned the UK was about to "start missing opportunities" to shape decisions by pulling out of the meetings before the Brexit deadline.
In a letter to the foreign secretary, Mr Tugendhat added: "The UK is bound by the decisions made in these meetings until it leaves the EU and with less than three months to go, it would seem to be a key time to ensure no last minute decisions are taken that could be harder to unpick once we have left."
Speaking in the House of Commons, the prime minister said in July that "all parties" needed to recognise that the UK's participation in the EU is coming to an end.
He continued: "There are very many brilliant officials trapped in meeting after meeting in Brussels and Luxembourg when they could be better deploying their talents in preparing to pioneer new trade deals and promoting a truly global Britain.
"I want to start unshackling our officials to undertake this mission right away."