Stefaan De Rynck, who is working closely with the bloc’s chief negotiator, said eurocrats were “for sure preparing” for the event of Britain crashing out of the club in March 2019.
But his comments directly contradict a speech made by the EU Council president Mr Tusk earlier this month, in which he explicitly said Brussels is not planning for such a scenario.
Speaking at an Institute for Government event in London yesterday, Belgian official Mr De Rynck said European leaders do not want to “add risk” to the Brexit process by “playing with time”.
He added Brussels “would certainly want to avoid going to the wire” on the two-year Article 50 period, telling reporters: “Brexit is a process we want to manage in a calm and rational way.”
However, he did break ranks with Mr Tusk – who is one of the bloc’s most senior officials – with his remarks that Europe is putting in place specific contingency plans for a no-deal Brexit.
Mr De Rynck insisted “decisive profess is within reach” in light of Theresa May’s Florence speech, but nonetheless said: “On advertising no deal, it is not something we want to advertise, oversell.
“There is a clear negative impact from no deal, I think that is clear, for both sides. Especially for the UK economy, but it not a scenario that we want to work towards.
“We are preparing for it, that is for sure, the 27, but it is not something we in the negotiation room want to bring in that negotiation room.”
The Belgian also insisted that nobody on the EU side “has any interest in slowing down the clock” amid accusations in Britain that Brussels could try to sabotage the talks to keep the UK in the club.
He said: “In terms of sufficient progress we need a method to be able to reassure the 27 of the solidity of the UK guarantees on how it will honour its commitments.”
“In terms of the guidelines for the future relationship as well as the possible transition, all of that can all come very quick. There is certainly a time pressure on all of us.”
Following the deadlocked fifth round of Brexit negotiations his boss, Mr Barnier, said “no deal will be a very bad deal” but hinted at secret preparations for such a scenario.
Responding to David Davis’ remark that Britain is preparing for such a scenario, he told reporters: “To be clear on our side we’ll be ready to face any eventualities and all the eventualities.”
However just two days before that Mr Tusk, whose job it is to act as a voice for the 27 member states, had categorically stated European capitals are not preparing for a no-deal Brexit.
He said: “We hear from London that the UK government is preparing for a ‘no deal’ scenario. I would like to say very clearly that the EU is not working on such a scenario.
“We are negotiating in good faith, and we still hope that the so-called ‘sufficient progress’ will be possible by December.”
But in a coded warning, he then added: “However, if it turns out that the talks continue at a slow pace, and that ‘sufficient progress’ hasn’t been reached, then – together with our UK friends – we will have to think about where we are heading.”
Following the EU Council summit last week, at which leader declared there has been no ‘sufficient progress’ in the talks, French president Emmanuel Macron accused Britain of “bluffing” over its no-deal plans.
British ministers have repeatedly stressed that they want to leave the club with a good agreement, including on trade, but have said it is a Government’s “duty” to prepare for all scenarios.