Political discussions on Brexit don’t often bring the house down but Labour MP Rachel Maskell could hardly contain herself on Wednesday when she appeared on BBC2’s Daily Politics show. Interviewer Andrew Neil was pummelling trade minister Greg Hands with questions about policy on the customs union. Hands flannelled and fudged. After repeated, failed attempts to penetrate the fog, Neil exploded: “Have you any idea what you are talking about?”, complaining that none of his questions had elicited the merest hint of an answer. Hands said he was the trade minister so he should know what he was talking about. “That is what worries me,” Neil barked back. Maskell, who had herself been subject to tough interrogation on Labour Brexit policy, sat between the two, unable to conceal her amusement.

The next day at business questions in the Commons, Andrea Leadsom, the leader of the house, was trying to answer MPs’ inquiries about the parliamentary timetable. Her opposite number, Labour’s Valerie Vaz, adopted an exasperated tone, wanting to know when the data protection bill would finally come before MPs. And – in the week that marked 100 years since women won the right to vote – was it not also time for the government to give its overdue response to a report on women’s equality? Was Brexit the only issue this government thought about?

The key pitfalls on the road to Brexit Read more

Both episodes highlight the deepening problems engulfing Theresa May and her divided party and government. Brexit is the subject around which all political discussion revolves, and on which most ministerial and parliamentary energy is spent. The other main hot political topic for debate at Westminster is over May’s chances of survival. That, of course, is intimately bound up with her ability to see Brexit through.

May’s party and government is split to such an extent that progress has become tortuously slow on the central mission. There is a sense of drift just as the real business of Brexit needs to be done. Without a parliamentary majority since the June election, May cannot lead without upsetting one side or other of the Tory European divide. Hands’s discomfort was caused by fear of coming down on one side or other on the critical issue of the customs union. So he said nothing at all. A government source said later that Hands was just saying “what Number 10 told him to do”. Nothing.

“She is just swinging between the positions of Jacob Rees-Mogg and Anna Soubry and stops somewhere in the middle,” says former Labour minister Chris Leslie.

Amid rumours that Tory MPs on both sides of the party’s ideological divide have sent letters to Graham Brady – chairman of the powerful 1922 Committee – demanding a vote of confidence in May, a veteran Tory backbencher said her only possible survival strategy was one of cautious equivocation at a time when decisive leadership was urgently required. “Her trouble is that if she moves in one direction she triggers ten more names to Brady, if she moves in the other direction she also triggers 10 more letters to Brady. So when we need to have a clear plan for Brexit, for the country, and for business, we have exactly the opposite. Paralysis.”

Indecision and evasion can only work for so long. In the next few weeks the prime minister could find herself defeated in both houses of parliament over key elements of her Brexit policy. It is likely that the Lords will pass amendments backing the UK’s permanent membership of the customs union. It could also ask for membership of the single market to be kept on the table. The Commons could then follow suit and back customs union membership for good, not least to solve Irish border issues that are among the most potentially explosive in the entire Brexit debate.

This would be a severe blow to the prime minister’s core hard-Brexit strategy. The right of her party would be furious, seeing Brexit slipping away, and might plot to remove her. But the hard-Brexit ideologues are also divided on the matter of who to replace her with – Boris Johnson, Michael Gove, Jacob Rees-Mogg. Neither are they certain that a change would really help their cause.

Facebook Twitter Pinterest Nicky Morgan says delay and slippage will be bad for everyone. Photograph: David Levene/The Guardian

Another catalyst for a parliamentary revolt against hard Brexit could be the 3 May local elections, when the Tories are likely to be routed in London and other cities. Heavy losses will spell more trouble as Tory MPs would fear an emergency Brexit-induced general election. In the meantime, May needs to have finalised arrangements for the two-year transition with the EU in time for a 22 March EU summit. That now looks unlikely. Relations between EU chief negotiator Michel Barnier and Brexit secretary David Davis hit a new low on Friday. Barnier is rejecting UK demands – ones that May has been forced to table by hardline Brexiters – that the UK should be able to block EU laws during the transition. The idea of a country that has just chosen to leave the EU wanting access to all its markets after departing but also wanting the right to block the 27 members from changing their rules has not gone down well in Brussels. There are now fears that the talks on the next phase – the post transition “end state” – will have to be delayed, casting the whole timetable into doubt.

Charles Grant, director of independent thinktank the Centre for European Reform, said: “There is a growing sense in Brussels that because the British are raising new difficulties on the transition, it will not be possible to agree it at the March summit.”

Lack of clarity on what the UK wants for the long term, Grant added, creates a risk that the EU will just dictate the terms of discussions from now on. “The longer the British delay saying what they want in terms of a future relationship, the greater the danger that the EU imposes something very narrow like a Canada-style agreement.”

From Brussels, the state of the UK government and the Brexit debate is viewed with incomprehension. Fabian Zuleeg, chief executive of the Brussels-based European Policy Centre thinktank, said: “The EU 27 and the institutions have watched the political chaos in the UK with a sense of disbelief and frustration. There seems to be a profound inability to come up with realistic negotiating positions, and a constant tendency for even the most limited agreements to be immediately undermined and recanted by the media, members of parliament and/or government ministers.”

Is a divided Brexit parliament up to the biggest task for generations? Read more

A final deal on the terms of withdrawal is due by October this year, but that now looks optimistic. Few expect all the detail to have been hammered out by then, given that the UK has yet to provide the EU with firm details of the relationship it wants. The Labour MEP Richard Corbett, a former senior adviser in Brussels, predicts that there may only be a “minimalist withdrawal agreement that takes us out but leaves all key issues to be settled later during the transition period”. The Brexit process, he believes, is way behind schedule because of UK indecision, May’s caution and her divided party.

Nicky Morgan, fired as education secretary by May in 2016 and now Tory chair of the Treasury select committee, said delay and slippage would be bad for everyone: “If the transition discussions slip, then presumably so does the chance of getting a final agreement that parliament can vote on in autumn 2018.

“The uncertainty about what happens in March 2019 isn’t good for anyone, particularly businesses and EU citizens. It only increases the chances of a disorderly Brexit. This cannot be what the government wants.” Least of all Theresa May, if she is able to survive that long.