Ireland has branded Boris Johnson’s decision to block an extension of the Brexit transition period “strange” and said the move will limit the UK’s options in the future.

The prime minister has said he will legislate to make it unlawful for the government to delay the end of the transition past the end of 2020 – limiting the time available to sign a trade agreement.

Speaking on Tuesday, Irish foreign minister Simon Coveney said the move amounted to the “UK deciding to tie itself in terms of options”, while senior EU officials said the scope of talks would have to be limited to adapt.

“Nobody is forcing the UK to apply for an extended transition period but they have the option to do it if they want to up until the middle of next summer, and what Boris Johnson is doing is essentially ruling out an option that was put into the withdrawal agreement for Britain,” Mr Coveney said.

“We all know that the negotiations post a British exit from the EU is going to be very complicated. It’s going to deal with multiple areas, not just a free trade agreement. It has also got to deal with security, data, fishing. There are multiple sectors which will require detailed negotiations.

“The EU hasn’t missed a deadline yet. It has been the UK that has missed deadlines in the past. I just think if we’ve learned anything from the first round of Brexit negotiations … [it] is that we shouldn’t be closing off options.”

Meanwhile, Sabine Weyand, one of the most senior officials on the EU side involved in negotiating the withdrawal agreement, told an event at the European Policy Centre: “Given all the signals ... we are well advised to take seriously that the UK does not intend to go for an extension of the transition and we need to be prepared for that.

“That means in the negotiations we have to look at those issues where failing to reach an agreement by 2020 would lead to another cliff-edge situation,” she said.

Ms Weyand is now the top civil servant at the EU’s trade department and will play a pivotal role in the next round of talks. Michel Barnier will lead a new EU taskforce on dealing with the UK.

The option to extend the transition period was written into the withdrawal agreement by Theresa May, and not removed by Boris Johnson during talks. During the period, the UK stays tied to EU rules and keeps free movement.

Nobody is forcing the UK to apply for an extended transition period but they have the option to do it if they want to up until the middle of next summer, and what Boris Johnson is doing is essentially ruling out an option that was put into the withdrawal agreement for Britain Simon Coveney, Irish foreign minister

Speaking on Tuesday, the prime minister’s spokesperson said: “The manifesto, which delivered an 80-seat majority for the prime minister, was explicit in ruling out any extension to the implementation period. This is a government determined to honour its promises to the British public and get Brexit done.

“Both the EU and the UK committed to agree the future partnership by the end of 2020 in the political declaration. Now, with absolute clarity on the timetable we are working to, the UK and EU will be able to get on with it and have a great future relationship wrapped up by December 2020.”

Asked whether businesses should be preparing for the possibility of the UK leaving the EU’s customs union and single market on 1 January 2021 with no deal in place on future trade relations, Mr Johnson’s spokesperson said: “Once the PM’s Brexit deal has been approved by MPs and we’ve left the EU on 31 January, we will have certainty on the terms of our exit.

“We will have guaranteed the rights of UK nationals, ensured that Northern Ireland remains part of the UK customs territory and that the UK will leave the EU whole and entire on 31 January. We will have settled our financial obligations and ensured that ongoing processes, such as customs and procurement, can come to an end under current rules without extra requirements being placed upon them.”

The spokesperson said that businesses would have to make similar preparations for new trading arrangements from 2021 onwards, whether the PM secures a Canada-style free trade agreement, as he plans, or takes the UK out of the EU without a trade deal.

Bizarre: Boris Johnson drives 'Brexit' digger through boxes Show all 8 1 /8 Bizarre: Boris Johnson drives 'Brexit' digger through boxes Bizarre: Boris Johnson drives 'Brexit' digger through boxes Conservative party leader Boris Johnson drives a JCB through a fake wall POOL/AFP via Getty Images Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson during a visit to JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson sits in a cab of a JCB during a visit to its cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Britain, December 10, 2019. Ben Stansall/AFP/Pool via REUTERS POOL REUTERS Bizarre: Boris Johnson drives 'Brexit' digger through boxes A sign made for a visit by Prime Minister Boris Johnson to the JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson reacts as he sits in the cab of a drives a Union flag-themed JCB, after driving through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty

“In all circumstances, we are leaving the single market and customs union, which means that we are leaving the EU regime associated with that,” said the spokesperson. “Businesses will need to prepare for life outside the EU customs regime in all circumstances and many have already done so.

“We conducted an extensive campaign in order to be ready for a 31 October departure, and businesses took significant steps to ensure that they were ready.

“For example, around 180,000 businesses have been registered for a UK EORI number over the last 12 months, which is necessary for businesses trading goods between the UK and anywhere in the world, including the EU, under a Canada-style FTA.”