The government's Brexit department said Britain wants to show that progress on the preliminary issues has been made and "we are ready to broaden out the negotiations" by the time of an European Union summit in October.
Senior members of the Government have declared the United Kingdom will not seek to remain in the European Union "by the back door" and will leave both the single market and the customs union when Brexit happens in 2019.
Fox, who was alarmed at the prospect of heading an global trade department unable to strike trade deals possibly for the rest of this parliament, admitted last month [paywall] that there was "still a discussion to be had" on this issue.
In a joint article for the Sunday Telegraph, they agreed that while a period of transition would be needed after 2019 to prevent a damaging "cliff-edge" break with the EU, it would be "time limited" and would mean pulling out of both the single market and the customs union. "And has that moment arrived yet?" she wrote in an article for The Mail on Sunday.
"We will await publication of the full position paper before making further comment and trust that the Irish government will engage seriously and pragmatically in helping to secure an agreement that benefits everyone. When we've left the customs union, we will build up on [relationships with other countries] by negotiating as an independent nation with the freedom to sign bilateral free trade agreements".
However, Liberal Democrat leader Sir Vince Cable said it was clear that Mr Hammond had lost his power struggle with the Brexiteers. They said the UK's borders "must continue to operate smoothly", that goods bought on the Internet "must still cross borders", and "businesses must still be able to supply their customers across the EU" in the weeks and months after Brexit.
David Jones, the pro-leave Tory who was the Brexit minister until the general election, told the BBC that Hammond had "rowed back from his previous position". Previously he had been downplaying the need for such a lengthy interim stage. "That means businesses need to have confidence that there will not be a cliff-edge when we leave the European Union in just over 20 months" time, ' they wrote.
According to reports, the Brexit negotiations have not begun well due to disagreements among Prime Minister Theresa May's team of ministers about the kind of deal they should be seeking.