The UK’s chief Brexit negotiator has called for “realism” from the EU ahead of the next round of trade talks beginning in London.
Lord Frost said there was “still time” for the two sides to agree a post-Brexit trade deal for next year.
But he said the EU needed to recognise the UK’s negotiating position came from that of a “sovereign state”.
His words follow a pledge from Boris Johnson to walk away from the talks if a deal isn’t done by 15 October.
The EU said it would “do everything in [its] power to reach an agreement” with the UK, but “will be ready” for a no-deal scenario.
The exchange also comes after No 10 revealed it would be introducing new legislation on customs rules in Northern Ireland, in case the negotiations fail.
The announcement has led to concerns from Brussels that the UK would not deliver on the withdrawal agreement, made ahead of its exit from the bloc in January.
But the government said the legislation would only result in “minor clarifications” and it was committed to the earlier deal.
The transition period – which sees the UK following a number of the EU’s rules while the two sides try to negotiate a trade deal – is due to end on 31 December.
If a deal is not made and ratified by parliaments across Europe by then, the UK will move onto trading with the bloc on World Trade Organisation rules, which would involve tariffs. Critics fear this would damage the economy.
Mr Johnson has ruled out any extension to the talks and, despite both sides admitting to little progress recently, he has set a deadline of mid-October – when the European Council is due to meet.
In an email to Conservative Party members on Monday, the prime minister said if there was no agreement by that date, “then I do not see that there will be a free trade agreement between us, and we should both accept that and move on”.