The European Commission said on Sunday: "A lot of work remains to be done," the BBC reported
In a statement it added that the "intense technical discussions" between the UK and EU officials in Brussels would continue on Monday before member states were updated on the progress at a meeting in Luxembourg on Tuesday.
The Commission's statement comes after UK Prime Minister Boris Johnson on Sunday told Cabinet Ministers that "significant work" was still needed.
Johnson however added that he could see a "way forward" to a deal "in all our interests".
The developments come as the government's agenda is to be set out in the Queen's Speech on Monday, which will also coincide with the State Opening of Parliament.
Ministers have said that the speech, the 65th of Elizabeth II's reign, will focus on "people's priorities".
Meanwhile, the UK and EU negotiating teams are due to meet again in Brussels on Monday, as efforts continue to reach a deal before a crucial summit on Thursday and Friday.
The government has said that if it could strike an agreement at the summit, it would introduce a withdrawal agreement bill to be voted on Saturday in a special Parliamentary session.
It is seen as the last chance before Brexit is due to take place at 11 p.m. on October 31.
The government has also announced that it intended to hold the Budget on November 6, with Chancellor Sajid Javid saying it will be "the first budget after leaving the EU".
Jon Trickett, Labour's shadow Commons leader, told the BBC that he would be "surprised" if the Budget went ahead as planned.
"We have no idea if they are going to get this Brexit proposal through the House or not," he said.
( With inputs from IANS )