The government is set to publish a "position paper", staking out the UK's desire for a smooth transition in leaving Europe.
Senior government officials said plans have been sent to Theresa May's cabinet outlining the goal of a transitional customs agreement, Politico reported today.
Sources said that if the proposal is agreed it will be published in the week of 14 August, alongside another document tackling the Northern Ireland border issue.
Momentum has been growing behind the idea that a smooth transition is needed before a new permanent relationship with the EU can be put in place.
The push for a transition deal, led by chancellor Philip Hammond, was this week backed by businesses and reinforced by comments made by Bank of England governor Mark Carney.
The publication would be the first of up to a dozen "position papers" to be put out between now and the October European Council summit, according to Politico.
"There is an awareness that we have to get to the European Council having shown seriousness,” an anonymous government official said.
It also emerged that the UK's Brexit negotiators will push to agree a final deal on citizens' rights for those from the EU living in the UK and British nationals elsewhere in Europe.