The Government on Thursday rejected the International Monetary Fund's advice that the UK should extend the Brexit transition period in order to buy more time for trade negotiations with the EU.

The end of 2020 deadline for a trade deal to be finalised was already tight before the coronavirus pandemic forced the cancellation of the last two rounds of negotiations and the quarantine of both sides' chief negotiators.

"We will not ask to extend the transition period, and if the EU asks we will say no," said the Prime Minister's spokesman.

"Extending would simply prolong negotiations, create even more uncertainty, leave us liable to pay more to the EU in future, and keep us bound by evolving EU laws at a time when we need to control our own affairs. In short, it is not in the UK's interest to extend," tweeted David Frost, Britain's chief negotiator.

On Wednesday, the UK and the EU agreed to hold large-scale online trade negotiations in a bid to avoid extending the transition, which would mean the UK paying the EU a membership fee.

Despite the risk of Britain leaving the Single Market without a free trade agreement – meaning trade with the EU would be on WTO terms – Downing Street continues to insist that the deadline, enshrined in law, will never be extended.

The EU, which insists it is up to Britain to make an extension request, says it is ready to negotiate a delay but that a request for a one-off extension of up to two years must be made by July according to the terms of the Withdrawal Agreement.

"It is best to be clear now and minimise uncertainty for business," the Prime Minister's spokesman added in a swipe at comments made by the IMF managing director, Kristalina Georgieva, which have enraged Brexiteers.

Mrs Georgieva said the UK and EU should not "add to uncertainty" by refusing to negotiate an extension. She told the BBC that, because of the "unprecedented uncertainty" arising from the pandemic, it would be "wise not to add more on top of it".

"It is tough as it is – let's not make it any tougher," she said. "My advice would be to seek ways in which this element of uncertainty is reduced in the interests of everybody – the UK, the EU and the whole world."