Boris Johnson’s cabinet is divided over how to proceed with Brexit, as the prime minister faces the stark choice of pressing ahead with his deal or gambling his premiership on a pre-Christmas general election.

After an inconclusive meeting with Jeremy Corbyn on Wednesday morning in an attempt to agree an acceptable timetable for parliament to consider the bill, the prime minister told MPs at Wednesday’s PMQs that he was awaiting the decision of the EU27 over whether to grant an extension before settling his next move. The EU’s decision is unlikely to come before Friday.

Some cabinet ministers, including the Northern Ireland secretary, Julian Smith, are cautious about asking for an election.

They believe the majority of 30 achieved by the government on the second reading of the Brexit bill on Tuesday suggests Johnson’s deal has enough support to carry it through all its stages in parliament.

Smith, who was Theresa May’s chief whip, has examined the various amendments to the withdrawal agreement bill, and does not believe any of them would necessitate pulling it. “Julian’s view is that the numbers are there,” said an ally.

Some Tory MPs said there also were serious misgivings on the back benches about the idea of an immediate election. “There’s a big, big fight going on, basically,” one said. “The parliamentary party is split 50/50. Personally, I don’t think an election is a very good idea.”

Another said: “I’d rather we focused more on passing the bill. It would be better to go to voters having finished the job. I feel that’s what most colleagues want.”

However, hard Brexit supporters appear to be more gung-ho, with leader of the House of Commons Jacob Rees-Mogg fearing support for the bill could yet fall away – if the 19 Labour rebels who backed it fail to secure the amendments they would like to see, for example.

Members of the Eurosceptic European Research Group (ERG) are also nervous about the legislation being amended in a way that they would find unacceptable – such as obliging the government to seek a customs union.

After Johnson’s meeting with Corbyn on Wednesday, Downing Street briefed that Corbyn had “made clear Labour have no policy except more delays” and hinted heavily that Johnson’s next move would be to ask MPs to support a December election.

“Any time that parliament gets a vote for delay, it will always choose delay,” said a Downing Street source. “Therefore, if this parliament is unwilling to vote for a deal, we will have to go for a general election.”

Despite the bullish rhetoric, Johnson’s chief whip, Mark Spencer, later met his Labour counterpart, Nick Brown, to explore whether a new timetable could be agreed for scrutinising the bill. That suggested the idea of trying to pilot the bill through parliament had not been ditched altogether – particularly if only a short extension is granted.

In the meeting between the two party leaders, held in the same Westminster office where Corbyn had previously confronted May, Dominic Cummings suggested MPs should be prepared to sit all night to hit next week’s Halloween deadline, according to one witness.

Meanwhile, Johnson has been trying to persuade EU leaders not to grant an extension – or at least to keep it short.

The PM spoke to Donald Tusk on Wednesday morning, telling the European council’s president, who has called for EU leaders to allow a further Brexit extension, that he does not personally want a delay. He also discussed the issue with the German chancellor, Angela Merkel.

Johnson’s spokesman said: “The PM was clear in restating his position that he does not believe that any delay beyond 31 October is in the interests of the UK or the EU and that we need to get the deal through parliament before that point.”

The prime minister was forced to write to the EU on Saturday to seek a delay until 31 January under a backbench-instigated law averting no deal, but had hoped to rush the bill putting his plan into law through parliament this week, to meet the current 31 October deadline.

Corbyn used all his questions at PMQs to ask Johnson about elements of the bill, including standards for environmental, consumer and workers’ rights, and the continued inclusion of Northern Ireland in elements of the EU’s customs union.

After Johnson incorrectly said there would be “no checks between Northern Ireland and GB [Great Britain]”, Corbyn accused him of having not properly read his own bill.

“The prime minister unlawfully prorogued parliament; he said he would refuse to comply with [the] law; he threw Northern Ireland under a bus; he ripped up protections for workers’ rights and environmental protections; lost every vote along the way; and tried to prevent genuine, democratic scrutiny and debate,” the Labour leader said.

“Even worse than that, he’s not that familiar with it.”