George Osborne will spell out how the government will balance the books and reform welfare when he delivers his first all-Tory Budget on July 8.
The Chancellor said the financial package would focus on "working people" and turning the Conservatives' election promises "into a reality".
Announcing the date in an article for The Sun rather than the more conventional method of a statement to Parliament - which is not yet sitting - Mr Osborne said: "On July 8 I am going to take the unusual step of having a second Budget of the year - because I don't want to wait to turn the promises we made in the election into a reality...
"And I can tell you it will be a Budget for working people."
Treasury aides indicated the Summer Budget would set out the Government's plan to deliver savings promised during the election campaign, and pay down Britain's debts in a "fair and balanced way".
Mr Osborne is expected to give more details of how ministers intend to shave £12 billion a year from the welfare bill while protecting the most vulnerable.
It is being branded as a "one nation" package to help spread the benefits of economic recovery across the country.