Cabinet minister Michael Gove says the EU “seem to be refusing to negotiate with the UK” over a new Brexit deal.
Mr Gove, who is responsible for no-deal planning, said he was “deeply saddened” that Brussels was, in his words, saying “no, we don’t want to talk.”
It comes after the EU said UK demands to remove the Irish backstop from Theresa May’s deal were unacceptable.
Irish PM Leo Varadkar has reiterated that the withdrawal deal, including the backstop, cannot be renegotiated.
The European Commission said it was willing to hold further talks, “should the UK wish to clarify its position”.
Theresa May’s deal has been rejected three times by MPs and as things stand, the UK will leave the EU on 31 October whether it has agreed a new one or not.
On Sunday, EU negotiators told European diplomats there was currently no basis for “meaningful discussions” and talks were back where they were three years ago.
A senior EU diplomat reportedly said a no-deal Brexit appeared to be the UK government’s “central scenario”.
Addressing those suggestions, Mr Gove said: “At the moment, it’s the EU that seems to be saying they’re not interested, they are simply saying ‘no, we don’t want to talk’.
“I think that’s wrong and sad, it’s not in Europe’s interests”, he added.
Many opponents of Mrs May’s deal cite concerns over the backstop – an insurance policy to prevent a hard border returning on the island of Ireland – which if implemented, would see Northern Ireland staying aligned to some rules of the EU single market.
It would also involve a temporary single customs territory, effectively keeping the whole of the UK in the EU customs union. These arrangements would apply unless and until both the EU and UK agreed they were no longer necessary.
Speaking on Tuesday in Belfast, Mr Varadkar told reporters he did not accept that a no-deal Brexit was unavoidable, adding there were “a number of ways” in which it could be avoided.
He said these options included ratifying Mrs May’s deal, further extending the UK’s EU membership, or the UK cancelling Brexit by revoking Article 50.
The BBC’s Brussels reporter Adam Fleming said the EU was grappling with how to deal with a prime minister in Boris Johnson who was demanding things they were not prepared to give.
He said the EU had not given up yet, and all eyes would be on the G7 summit in France at the end of August, which many believe could be the moment of truth – the point at which a no-deal Brexit may become inevitable.