Labour will today accuse Theresa May of planning a ‘Bankers' Brexit’ which will ignore the needs of manufacturers and small firms.

The Prime Minister is pursuing “sweetheart” deals for financial services giants in the City of London rather than the interests of the wider economy, Shadow Chancellor John McDonnell will claim.

In a speech at the Institution of Mechanical Engineers, Mr McDonnell will argue only Labour can be trusted to deliver a successful Brexit, by preparing the country for the challenges ahead.

And he will say: “Whether by design or by default, this shambolic Brexit will end up where the Tories always end - looking after the few, not the many.

“Already, Tory Cabinet ministers are looking to cook up special deals for their friends in the City of London, while Tory backbenchers want to attack hard-won workplace rights.

“They want a “Bankers’ Brexit”, in the interests of an elite few, not the majority. They'll cut a deal for finance, but ignore our small businesses and manufacturers.

“Labour will fight for all our businesses to have single market access, not just the favoured few.”

The criticisms follow heavy hints, from Chancellor Philip Hammond, that special arrangements will be struck to avoid damage to the City of London from EU withdrawal.

Theresa May's Brexit strategy like a plan from Baldrick - Corbyn

Meanwhile, Ms May has made curbing immigration her red line in the exit negotiations – making Britain’s exit from the trading arrangements of the single market increasingly likely.

The Prime Minister has vowed to protect workers’ rights currently guaranteed by the EU, but some Tory backbenchers want to rip them up.

Mr McDonnell will seek to draw a distinction between “those who have voted Conservative” and what he will call “the Tory establishment”.

He will say: “Like me, you will have friends who have voted Conservative. They don’t want a Bankers’ Brexit any more than I do.

“The simple truth is that the Tory establishment cannot be trusted to make a success of Brexit. They want to take control for themselves, not the many.

“They want to turn Britain into a Singapore of the North Atlantic.”

The speech comes against the backdrop of a huge lead in the opinion polls for the Conservatives when it comes to economic competence.

In next month’s autumn statement, Mr Hammond is expected to “reset” economic policy in the wake of Brexit, easing up on George Osborne’s deficit reduction programme.

Nevertheless, Mr McDonnell will insist only Labour is “committed to serious investment” to allow Britain to “power through the stresses of Brexit”.

He has adopted the fiscal rules of Ed Miliband and Ed Balls, seeking only a surplus on day-to-day spending, excluding investment spending.

Mr McDonnell will pledge to “work with our European neighbours to protect our key industries like steel”, as well as to tackle tax avoidance by the likes of Google.

And he will say: “Labour will take back the economic levers of power currently in the hands of the EU, such as over state-aid rules, and return them to the people.”