The Prime Minister will confront her failed general election gamble head-on, calling on her opponents to share their plans for delivering a fairer country.
It comes amid rumours of a possible challenge to Mrs May’s leadership after the Conservatives lost their majority, forcing the party to dump much of its election manifesto and leading to open conflict between cabinet ministers on whether to soften the squeeze on public spending.
However, despite facing mounting questions over how her minority government will deliver a beneficial Brexit deal, Mrs May’s comments barely mention her plan for leaving the EU, with little sign of compromise on Tory red lines.
Downing Street and pro-Brexit Tory MPs have resisted growing calls across party lines for a Norway-style deal that keeps the UK inside the EU single market.
Yesterday the likely Liberal Democrat leader Sir Vince Cable said he believed Brexit “may never happen” because of the difficulty in striking the right deal and getting it through a divided parliament.
The Scottish Government said Mrs May had to re-open talks with devolved administrations and compromise on leaving the European single market and customs union.
In a speech tomorrow, Mrs May will return to the themes she set out in her Downing Street speech on being appointed Prime Minister, which focused on fighting “burning injustices” such as racism and inequality.
She will reiterate that the vote to leave the EU was the product of “a deeper and more profound call for change across our country” that demands “a commitment to greater fairness in our country”.
Unveiling a report following a nine-month review of employment practices in the modern digital economy, Mrs May will repeat her promise to harness a “period of great national change” to make Britain “a country that works for everyone, not just a privileged few”.
She is expected to say: “Though the result of last month’s general election was not what I wanted, those defining beliefs remain, my commitment to change in Britain is undimmed; my belief in the potential of the British people and what we can achieve together as a nation remains steadfast; and the determination I have to get to grips with the challenges posed by a changing world never more sure.
“I am convinced that the path that I set out in that first speech outside Number 10 and upon which we have set ourselves as a government remains the right one.”
She is expected to add: “The reality I now face as Prime Minister is rather different.
“In this new context, it will be even more important to make the case for our policies and our values, and to win the battle of ideas both in Parliament as well as in the country.”
The Prime Minister will ask opposition parties to “come forward with your own views and ideas about how we can tackle these challenges as a country”.
“We may not agree on everything, but through debate and discussion – the hallmarks of our parliamentary democracy – ideas can be clarified and improved and a better way forward found,” she will say.
Andrew Mitchell, the former Conservative chief whip, played down comments printed in the Mail on Sunday in which he is reported to have said Mrs May was “dead in the water” and would have to resign following the general election.
He is reported to have said at a private dinner that the Prime Minister had “lost her authority” and was “weak”.
Mr Mitchell ran David Davis’s failed 2005 leadership bid, with the Brexit Secretary considered the leading contender to replace Mrs May in the event of an internal challenge.
The account of the gathering on 26 June, the day Mrs May struck a deal with the DUP to prop up her minority administration in Parliament, was “overheated”, Mr Mitchell said.
The comments follow reports last week that junior ministers in Mrs May’s government were preparing to resign en masse in protest at her leadership.
But the Justice Secretary, David Lidington, yesterday said the flurry of “gossipy stories” was being fuelled by “too much sun and too much warm prosecco” on the Westminster summer party circuit.
The Scottish Government’s Brexit secretary Michael Russell called on Mrs May to co-operate with the SNP on proposals to keep the UK in the single market.
“If the Prime Minister is genuinely interested in creating a consensus then Scotland should have a seat at the negotiations to leave the EU,” Mr Russell said.
“The Scottish Government already put forward a range of proposals last December which the UK government thought they could blithely ignore.
“But the election result was a comprehensive rejection of the Tory plans for an extreme hard Brexit. Single market membership – whether for the UK or Scotland – must now be back on the table.
“Theresa May couldn’t have been clearer. She called this election to secure a mandate for a hard Brexit position, and the electorate snubbed her.”