Britain has been warned by Brussels that the country is staring into the “abyss” as the EU prepared to outline new no-deal measures in the wake of the latest Commons votes.

EU sources said their focus had to be with dealing with the UK probably crashing out of the bloc in two weeks’ time, with patience increasingly wearing thin in the EU’s capitals.

“All we can do is sort our house out,” one EU diplomat said. “But the failure to even find a small majority for any solution offers little indication that there is an orderly way out of this.”

Guy Verhofstadt, the European parliament’s Brexit negotiator, tweeted that the last stage of the indicative vote process, to be held on Wednesday, offered the last hope of avoiding a no-deal. MPs plan to bring back a smaller number of proposals to the Commons in the hope that a compromise position can be found.

He said: “The House of Commons again votes against all options. A hard Brexit becomes nearly inevitable. On Wednesday, the UK has a last chance to break the deadlock or face the abyss.”

Before the vote, EU officials had said Britain would be on track to leave the EU by 22 May if the Commons ordered Downing Street to negotiate a customs union.

The desire to negotiate an ambitious customs deal could be swiftly written into the political declaration and formally signed off at the EU leaders’ summit on 10 April. But the customs union proposal, tabled by the former chancellor Ken Clarke, lost by three votes on Monday night.

It was one of four proposals, along with the second referendum, the common market 2.0 proposal and revocation of article 50, that failed to achieve a majority.

Speaking in Berlin earlier in the day, Jean-Claude Juncker had called for MPs to coalesce around a post-Brexit vision, and hinted at the danger that the EU’s patience was being stretched.

The European commission president said: “We now know what the British gov does not want but we still don’t know what they do want. In comparison to the British parliament, a sphinx is an open book. We need to get the sphinx speaking. We’ve had enough of the silence.”

Juncker, who described David Cameron as “one of the biggest destroyers in the modern era” for his role in the referendum, went on: “If the British have not left by the 12 April and there will be a delay, then they have to take part in the elections. Whether I wish for this to happen or not is another matter. I wish we could find an agreement with the Brits by 12 April so this question wouldn’t need to be asked.”

The EU has already published a series of time-limited contingency measures, including legislation to keep flights in the air and road haulage routes open in the event of a no-deal Brexit. Further details on how the Irish border will be kept open are expected along with other measures designed to protect EU interests after a cliff-edge Brexit on 12 April.

Senior EU sources said it would still be possible for the UK to leave by 22 May if the prime minister’s deal or one including a customs union were backed this week by MPs.

Earlier, Verhofstadt had described a vote in favour of a customs union as “really the best thing that could happen”. He said: “That new political statement can then be approved at a European summit on 10 April and then we will give the British the opportunity to formalise it in English legislation by 22 May.”

Verhofstadt’s optimism was not matched in all the EU’s capitals, given the British prime minister’s previous rejection of a customs union.

In a speech on Saturday, Germany’s EU minister, Michael Roth, told an audience in Berlin: “Brexit is a big shitshow. I say that now very undiplomatically,” and added that “90%” of the British cabinet had “no idea how workers think, live, work and behave”.

Labour backing for the idea of a customs union includes the condition that there is a British say in the EU’s trade policy. Brussels would probably seek to avoid a row on this issue ahead of the withdrawal agreement and political declaration finally being ratified by the Commons.

But one EU official close to the negotiations admitted the UK would face stiff opposition to anything more than a symbolic consultative role.“When you consider EU trade deals are mixed agreements, there are the member states’ views, the European commission, and the voice of the European parliament,” the official said. “What can you do with a third country? Not much.”