Speaking at an event in Yorkshire today, Mr Miliband will unveil plans for “early legislation” in the next parliament requiring employers to offer a regular contract to new recruits after 12 weeks.

Zero-hours contracts are a bone of contention in the run-up to May’s general election.

The Conservatives have banned exclusivity clauses – which meant people on the contracts couldn’t look for other work, but have stopped short of further action, claiming they are useful to some working people.

Labour will put legislation to ‘ban’ the contracts in their current form in its first Queen’s Speech, should it win the election.

It argues the contracts have become a “symbol of a low-wage, low-skill, economy where stagnant wages and falling productivity” are offshoots of Tory policy.

“The explosion of zero hours contracts tells us the answer to that question in Britain right now,” said Mr Miliband.

“There are now three times as many people on zero hours contracts as there were when this government came to power; a 20 per cent increase in the last year alone, 1.8 million work contracts without guaranteed hours.

“It is leaving people without a reliable income, not knowing from one day to the next how much work will be coming in, unable to plan from one week to the next.”

Zero-hours contracts have become a symbol of the Tories’ failing economy. Here’s how I’ll tackle them: https://t.co/UIOkMtoRcM

— Ed Miliband (@Ed_Miliband) April 1, 2015

But businesses are increasingly siding with the Conservative stance. Today 300 business leaders pledged support for the Tories, while the CBI accused Labour of “playing with the jobs market”.

CBI director general John Cridland said: “The UK’s flexible jobs market has given us an employment rate that is the envy of other countries, so proposals to limit flexible contracts to 12 weeks are wide of the mark.

“Of course action should be taken to tackle abuses, but demonising flexible contracts is playing with the jobs that many firms and many workers value and need.”

Meanwhile the Institute of Directors said Labour’s pledge was “unnecessary and damaging”.

Christian May, head of communications and campaigns, said: "Labour's proposals go too far. They are unnecessary and potentially damaging. Frankly, this is an example of politics trumping good policy.

"A cross-party consensus has already emerged that would ban the use of exclusivity clauses, but limiting the use of a zero hours contract to just 12 weeks would apply rigid controls on an important element of our flexible labour market.”