Mr Cooper told Emily Maitlis on BBC Newsnight: "I can write about the Queen who 67 years into her reign probably wants to get involved with Brexit, not at all".
If Mr Johnson tried to "bury himself" in Downing Street and tried to stop a new government taking over, the monarch would step in despite the risks of getting embroiled in politics, the Remainer source said. The two are likely to be linked.
'It's why Brexit hasn't been delivered and why it won't be until there are Brexit MPs in the House of Commons to make up the numbers'.
One of the EU's Brexit negotiators told the meeting that the G7 summit in France at the end of August could mark the point where it became clear a no-deal Brexit was inevitable. On Aug. 4, even Conservative Party Chairman James Cleverly didn't rule it out.
Constitutional experts said Mr Johnson is not legally compelled to leave No 10 even if the Commons passes a no confidence motion.
Such a scenario would lead to major disruption on both sides of the Channel.
The Labour MP for Vauxhall told left-wing, pro-Brexit pressure group Labour Leave that the party can no longer take its supporters for granted, saying: "I think Labour needs to realise that many disillusioned Labour supporters now have somewhere to go to".
However, during that time, another member of his governing Conservatives could also try to secure a majority, as could the main opposition Labour party.
In recent days there has been speculation Parliament could oust Johnson from his premiership with a No Confidence vote and install a "unity prime minister" in his place, who would then delay Brexit and call a general election. Serious for food prices, for medical supplies, for trade, for investment, and drive us straight into the hands of the sort of trade deal that Donald Trump wants to do with Boris Johnson.
During his time in Government, Mr Osborne passed the Fixed Terms Parliament Act in 2011.
Speaking during a visit to the Pilgrim Hospital in Boston, Lincolnshire - one of the hospitals set to benefit from the increase - Mr Johnson was adamant that the £1.8 billion was new money.
One of his top advisers, Dominic Cummings, believes this is an option if Parliament plays hardball, according to a report in the Sunday Telegraph newspaper this weekend.
The spokesman said: "It is my job to set out the PM's position, and that is that the United Kingdom will be leaving the European Union on October 31 whatever the circumstances".
Since last month their numbers have been boosted potentially by a number of former ministers, such as ex-chancellor Philip Hammond, who previously voted with the Government but have said they will now work to stop no-deal.
"We hope that this development will help us to see and treat patients more quickly and ensure that everyone is getting the right level of care that they require".
In any case, a hard Halloween Brexit on October 31st seems increasingly unlikely.