If Boris Johnson is re-elected as prime minister on December 12, Javid said the government would set itself new fiscal rules allowing it to spend up to 3% of annual economic output on infrastructure, higher than a historical average of around 1.8%.
Speaking in Manchester, northwest England, Finance Minister Sajid Javid said the Tories would "get Brexit done", allowing Britain to move on after three years of uncertainty over its European Union exit.
However Javid will say that Labour's plans would put at risk a "decade of recovery" under the Conservatives. "Before he spends any of that money, the economy will be ruined".
Mr McDonnell confirmed Labour would commit to an "additional £150 billion" for a new Social Transformation Fund to be spent over the first five years of a Labour government.
He said this would "begin the urgent task of repairing our social fabric that the Tories (Conservatives) have torn apart".
"Our aim as a Labour government is to achieve what past Labour governments have aspired to", he will say. An irreversible shift in the balance of power and wealth in favour of working people'.
Both parties were concentrating on the economy on the second day of the official campaign after their early efforts were marred by unplanned events.
Watson, who is not standing again for election, said he was stepping down for "personal not political" reasons, and would be campaigning in future on health issues.
"The clash over the economy â€" one of the key election battlegrounds â€" takes place as Corbyn appeared to strengthen his grip on the party with the shock resignation of deputy leader Tom Watson.
McDonnell said in a speech that government debt would rise but a higher investment would boost public assets and strengthen the public sector.
But nine years of public spending cuts to reduce an oversized budget deficit have also taken their toll on voters, with many public services financially stretched and polls suggesting little appetite for more austerity.
Prime Minister Boris Johnson's Conservatives confirmed an end to a decade of belt-tightening with new plans to borrow to invest, while attacking the rival Labour party for pledging even greater largesse.
Bank of England Governor Mark Carney said on Thursday there was a prospect of Britain finally securing its exit from the European Union - something Johnson hopes to achieve by winning a majority in the election - which could boost growth.