Ten days ago, members of the European Research Group of Eurosceptic Conservative MPs were feeling upbeat about their prospects, believing the tide was turning away from Theresa May’s Chequers deal and towards their preference for a harder Canada-style Brexit. And then came the week from hell.

Allegations about Boris Johnson’s private life plastered across the newspapers kept the Brexiteers’ talisman firmly off the field of play in what was supposed to be the week the ERG mounted its challenge to Chequers.

Instead, two public meetings held by senior Leavers to put forward an alternative Brexit plan were judged a damp squib both inside and outside the ERG camp. A meeting of the Economists For Free Trade group was remembered only for an FAQ sheet handed out to guests which answered questions such as “Wouldn’t Foreign Direct Investment into the UK inevitably fall?” simply with the word “No”.

As they licked their wounds at the end of a bruising week, dismayed members of the ERG told BuzzFeed News that they may have blown their big chance to seize control of Brexit.

While the detail contained in their plans for the Irish border, unveiled at a lacklustre press conference on Wednesday, was not immediately debunked, there was little pickup in the media and they have been unable to successfully sell their message.

“If I am honest, I despair,” one senior ERG MP told BuzzFeed News: “After what I saw my heart sank."

“We have no actual PR operation whatsoever,” the MP said. “We haven’t got any money. We are a research group with enough funding for one researcher.”

There are concerns that there is no media strategy in place for the ERG to keep their plan in the news over the next two weeks. “That was it,” confirmed one ERG insider with knowledge of the group’s workings.

Under the new editorship of Geordie Greig, on Wednesday the Daily Mail newspaper backed Chequers and mocked the “Brexiteer disarray” of the ERG operation. Another MP said: “The abiding image of our week is that photo of Boris, [Jacob] Rees-Mogg and Peter Bone with their heads in their hands”.

A prominent Leaver who is not a member of the ERG told BuzzFeed News they were not surprised by the group’s shortcomings. “It was totally predictable that the ERG would fuck it up. This is why Vote Leave did not allow Bernard Jenkin and Owen Paterson anywhere near the campaign. It would have been two months of a shitshow like this week”.

At a meeting of the group of Tuesday night, around six MPs spoke openly about attempting to remove May. As one present recalled, “no one in the room stuck up for her”, though most stayed silent. But the news of the open revolt chatter quickly leaked out of the room and onto ITV political editor Robert Peston's Facebook page, ignited another backlash against the group from Tory ministers and backbenchers who accused them of going too far.