Dominic Raab has claimed Britain will be in a better position to negotiate a “good deal” with the European Union if it crashes out of the bloc before the end of October.

The foreign secretary believes a no-deal scenario could provide more leverage in the context of a free trade agreement and resolve long-standing issues such as the Irish backstop.

The MP for Esher and Walton in Surrey also suggested the EU’s “stubborn” behaviour would be responsible if the UK left without a deal and refused to endorse Boris Johnson’s claim during his campaign for the Conservative leadership that the prospect of a no-deal Brexit was a-million-to-one against.

On leaving without a deal after 31 October, Raab told BBC Radio 4’s Today programme: “The prospect of reverting and getting a good deal will be easier after we have left if that is the case. The reason being we do as an independent third country and less subject to effectively the demands of the EU as we are now.”

During a hustings event in June, Johnson said the chances of a no-deal Brexit were a “million-to-one against” despite repeatedly promising to leave by the deadline.

The government has stepped up preparations for such an outcome in recent days. Michael Gove said over the weekend that officials were “operating on the assumption” that a deal would not be struck.

Raab insisted the government wanted to strike a deal with the EU and would make renewed efforts to reach out to Brussels in meetings during the summer parliamentary recess.

However, he said there “must be some change from the EU”.

“I think what people want to know is the reassurance first of all we are going to deliver Brexit by the end of October – that is the massive trust issue here, if you want to frame it in those terms.

“Secondly, while we want a good deal with our EU friends and partners we must abolish the undemocratic backstop. We will keep straining every sinew if a deal is to be done, but the EU will need to move [its position].

“If they don’t it is incredibly important we are ready for all eventualities.”

Quick Guide What is the Brexit ‘backstop’? Show What is the original ‘backstop’ in the withdrawal agreement? Variously described as an insurance policy or safety net, the backstop is a device in the withdrawal agreement intended to ensure that there will not be a hard border between Northern Ireland and the Republic of Ireland, even if no formal deal can be reached on trade and security arrangements. It would mean that if there were no workable agreement on such matters, Northern Ireland would stay in the customs union and much of the single market, guaranteeing a friction-free border with the Republic. This would keep the Good Friday agreement intact. Both the UK and EU signed up to the basic idea in December 2017 as part of the initial Brexit deal, but there have been disagreements since on how it would work. The DUP have objected to it, as it potentially treats Northern Ireland differently from the rest of the UK, creating a customs divide in the Irish Sea, which is anathema to the unionist party. Hardline Tory Eurosceptics also object to it, as they perceive it to be a trap that could potentially lock the UK into the EU’s customs union permanently if the UK & EU cannot seal a free trade agreement. That would prevent the UK from doing its own free trade deals with nations outside the bloc. What was added to May’s withdrawal agreement? Joint interpretative instrument

A legal add-on to the withdrawal agreement was given to Theresa May in January 2019 to try to get her deal through the UK parliament. It gives legal force to a letter from Jean-Claude Juncker and Donald Tusk, the presidents of the commission and council. This stated the EU’s intention to negotiate an alternative to the backstop so it would not be triggered, or, if it was triggered, to get out of it as quickly as possible. Unilateral statement from the UK This set out the British position that, if the backstop were to become permanent and talks on an alternative were going nowhere, the UK believes it would be able to exit the arrangement. Additional language in political declaration This emphasises the urgency felt on both sides to negotiate an alternative to the backstop, and flesh out what a technological fix would look like. However, it failed to persuade the attorney general, Geoffrey Cox, who said that while it ‘reduces the risk’ of the UK being trapped in a backstop indefinitely, it does not remove it. What happens next? Boris Johnson declared the Northern Ireland backstop ‘dead’ during his leadership campaign, and promised to throw it out of any deal he renegotiated with the EU. The EU has repeatedly stated that it will not reopen the withdrawal agreement for renegotiation. Daniel Boffey, Martin Belam and Peter Walker

The former Brexit secretary added: “We want a good deal but since the remarks [Johnson made] we have had a series of fairly stubborn positions staked out from the EU. In fairness you would expect that; it’s only a few days into this administration.

“If they stick to that line – they’re not willing to move at all, they have reaffirmed that – we must be prepared to give the country the finality it needs, to prepare businesses and people more broadly.”

Raab added there was a mandate for a no-deal Brexit and “Brussels isn’t the only game in town”, with opportunities for trade deals with the US, Latin America and Asia.

His remarks come after the Irish prime minister, Leo Varadkar, said on Friday that “more and more people in Northern Ireland will come to question the union” if the UK crashed out of the EU.

Meanwhile, the former Conservative minister Sir Oliver Letwin said Theresa May’s government had not done enough work to prepare for a no-deal Brexit.

Letwin told the BBC: “I think there should have been considerably more preparation even stretching back a couple of years, but we are where we are and although, as you’ve just said, I don’t think it’s very sensible for this country to be heading towards a no deal. We have to accept this government intends, if it can’t get the deal it likes, to take us out without a deal.

“So we may very well find ourselves leaving without a deal, and in that context it makes abundant sense to do everything that can be done in the next three months to prepare the country to minimise the impact of it.”