Chairman of the European Research Group (ERG) Steve Baker has called on the prime minister to reverse his rejection of an election pact with Nigel Farage, with other Tory Spartans saying the agreement is needed to win Brexit-supporting seats in Labour heartlands.

Last week, the former Brexit minister Steve Baker called on his own party to agree a non-aggression pact with the Brexit Party, where each party would strategically field candidates so as not to split the Brexit-supporting vote. Reports circulated that members of the ERG were already holding tentative discussions with Farage and his party over a partnership.

However, Prime Minister Boris Johnson’s office rejected the offer of a pact with scorn and in light of that, the ERG chairman told the Daily Mail on Thursday that the Brexit Party contained “many high quality people” who were conservative by nature, and wondered how a Brexit-supporting majority in the House of Commons could be won in a General Election without Farage’s help.

“I am still waiting for someone to explain to me how we win a general election and reunite the Conservative coalition without committing to some sort of arrangement — even an informal one — with the Brexit Party,” Mr Baker said.

Another senior Conservative told the newspaper that the Tories and Brexit Party would need to come to an arrangement, particularly in Leave seats dominated by Labour, where the electorate would not ever consider voting Conservative, saying: “There will be Leave seats where Labour are first and maybe the Lib Dems are second and where we have never stood a chance where the Brexit Party could have the best chance.”

Mr Baker remarked as much on Thursday, when he shared on social media an academic analysis that points to Labour 2017 voters being “unlikely to vote Conservative regardless of their Brexit identity”, where a University of Bristol political sociologist stated, “Those Labour leavers are unlikely to be Conservative converts,” suggesting rather it would be fertile ground for the Brexit Party.

Mr Farage has been reaching out to the Tories for a number of months while he has been amassing hundreds of Brexit Party candidates in preparation for an autumn snap election. The politician has already said that he would not field candidates in seats held by Tory Brexiteers who back a no deal, known as the “Spartans”, and said he was willing to come to arrangements in other constituencies in exchange for the Conservatives standing down in 80 to 90 seats in the North East, Midlands, and Wales — the Labour Leaving heartland, where the Tories would likely not win.

The BBC reported on Friday that the Brexit Party had taken over its first council, in Hartlepool in the North East of England, where seven out of ten people voted to leave the EU in 2016. The Brexit Party had agreed a pact with nine independent councillors and three Conservatives at Hartlepool Borough Council, the Brexit Party and Conservative Coalition replacing the Independent Union and Conservative Group. The move also represents a blow to Labour, which lost control of dozens of seats in the May local elections, resulting in the loss of control of all five Tees Valley councils.

A recent survey found that a plurality of Britons back a Johnson-Farage pact in order “to secure a parliamentary majority for a no deal Brexit”; broken down by party affiliation, 89 per cent of Brexit Party supporters and 69 per cent of those who intend to vote Conservative agreed.

However, in an extraordinary and public rebuff, a Downing Street spokesman said this week that Mr Farage was not a “fit and proper person” and who “should never be allowed anywhere near government”.

It is believed that the prime minister’s senior advisor Dominic Cummings is blocking the partnership, the former Vote Leave figure having clashed with Mr Farage and Leave.eu during the 2016 referendum.

Mr Farage had warned that the promise of a pact would only come if Johnson dropped the pursuit of renegotiating Theresa May soft-Brexit treaty and fully embraced no deal, otherwise he would challenge the Tories in every seat across the country.