Sajid Javid will announce an increase in Britain's defence spending this week, as he commits the UK to continuing to play a "leading role on the global stage" after Brexit.

The chancellor is expected to announce a modest increase in the 2.1 per cent of the UK's gross domestic product (GDP) that is currently spent on defence.

Mr Javid has said he will keep within the Government's budgetary rules when he announces a one-year "spending round" for government departments on Wednesday.

But on Saturday the Resolution Foundation, a prominent think tank, claimed that he was on course to break the fiscal rules on public borrowing, on the basis of spending and tax cuts currently planned by ministers.

The decision to increase defence spending comes after Boris Johnson pledged to "exceed the minimum two per cent Nato spending target" and "fund defence fully", during the Tory leadership campaign.

It will be included in a Commons statement Mr Javid will make on Wednesday, which will increase expenditure on schools, the police and NHS.

On Saturday night the Treasury said the announcement would also include a £90 million boost for the country's embassies and consulates around the world as well as £60 million to extend a campaign promoting trade with the UK.