Boris Johnson has accused Remainers of using the Irish border issue to try to frustrate Brexit.
The Foreign Secretary said anti-Brexit politicians were attempting to keep Britain in the customs union, "effectively the single market," by saying it is the only way to avoid a hard Irish border.
It comes after a letter sent by Johnson to Theresa May emerged, saying the Government should focus on preventing the frontier becoming "significantly" harder, reigniting a row over the issue.
With the EU preparing to set out draft legal plans today (February 28) to ensure Northern Ireland is aligned with Brussels rules if no other solution can be found to avoid a hard border with the Republic, Johnson hit out at the "inverted pyramid of objections" over the issue.
Speaking to reporters after returning from a jog in the snow, he said: "What is going on at the moment is that the issue of the Northern Irish border is being used quite a lot politically to try and keep the UK in the customs union, effectively the single market, so we cannot really leave the EU. That is what is going on."
Johnson said his letter showed "there are very good solutions" that would prevent a hard border for goods crossing the Irish border, while "allowing the UK to come out of the customs union, take back control of our tariffs schedules, take back control of our commercial policy, take back control of our regulation."
The former London mayor also repeated widely criticised comments likening the Irish border to congestion charge zones in the capital, asking a reporter: "I don't know whether you have ever driven into the congestion charge zone from outside the congestion charge zone - have you?
"Do you slow down? Do you feel any let or hindrance? Do you check your progress? Do you brake? Do you?"
Brussels' chief negotiator, Michel Barnier, said there would be "no surprises" in the 120-page draft document, which will cover the political agreements reached between May and Commission president Jean-Claude Juncker in December.