Chancellor Philip Hammond has said any "transitional deal" in the immediate period after Brexit must end by the time of the next general election. He said there must be "business as usual, life as normal" for Britons as the UK exits the EU. "Many things would look similar" the day after Brexit - on 29 March 2019 - as the UK moved gradually towards a new relationship with the EU, he said.
But he added the transition must end by June 2022, before the next election.
Meanwhile the Guardian has reported that Malta's PM Joseph Muscat has said he is "starting to believe that Brexit will not happen".
The UK is due to leave the EU at the end of March 2019, but there has been increasing talk of a "transitional" or "implementation" stage to smooth the Brexit process, before a new long-term relationship with the EU is in force.
It could mean a period during which some EU rules would continue to apply to the UK after it has technically left the bloc. Newspaper reports have suggested these could include allowing the free movement of people for a period, something seen as a key issue in the vote to leave the EU.
Mr Hammond also appeared to acknowledge that it could mean new trade deals with non-EU countries could not be signed during that period, but said it would "take some time for us to negotiate" them and the important thing was to be able to "get started on that process".
The chancellor, who has been calling for Brexit talks to prioritise the economy, told BBC Radio 4's Today programme: "I can't tell you a precise period of time because we haven't had that discussion yet, it will be driven by technical considerations - how long it will take us to put the necessary arrangements in place.
"People have talked about a year, two years, maybe three years... I think there's a broad consensus that this process has to be completed by the scheduled time of the next general election, which is in June 2022."
On Thursday, Immigration Minister Brandon Lewis said it was a "simple matter of fact" that EU free movement rules - seen as a key issue in the EU referendum campaign - would not apply after 2019.
Mr Hammond said he was right to say so because freedom of movement was an EU concept and the UK would leave the customs union and single market on 29 March 2019.
But he said the question was "what happens next" so that British people and businesses could "get on with their lives" without "massive disruption".
"On the first day after we leave the European Union, of course many things will look similar because that is the starting point."
'Matter of fact'
He hoped that "in the immediate aftermath ... goods will continue to flow across the border between the UK and the EU in much the same way as they do now".
On whether EU citizens would continue to be free to enter the UK, he said it would be "some time before we are able to introduce full migration controls between the UK and the European Union".
"That's not a matter of political choice, it's a matter of fact. We have to put in place quite a lot of new infrastructure, we will need a lot of new people, we will need new IT systems... This is going to take a while to deliver."
But he added: "What people in this country will want to know is that the day after we leave the European Union they are still able to go about their business.
"They will want to know that when they go to the supermarket, French and Spanish produce will be on the shelves, in the normal way. They will want to know that if they want to travel to Europe or go on holiday they will able to go to the airport, get on a plane and fly to their destination.