An extra £140m has been found in Treasury coffers for flood repairs and protection, the Chancellor will announce on Wednesday.

In his financial blueprint George Osborne will say he has found the extra cash to pay for repairs and to help protect homes at risk from future tidal surges and heavy rainfall.

It comes after Norfolk farmer and drainage boss Henry Cator told MPs that Norfolk and Suffolk came within inches of being flooded when the tidal surge struck the East Coast in December.

The former chairman of the Royal Norfolk Agricultural Association, who is now chairman of the Association of Drainage Authorities, told the environment select committee it was time the Treasury realised that proper money needed to be invested in maintenance.

Treasury sources said the extra money was needed to repair homes to “retain the high level of protection they received this winter”.

He said that while existing flood defences protected around 1.4 m properties and about 965 square miles of farmland since the beginning of December – the government wanted to improve on that in the future.’

‘The exceptional weather this winter has led to damage in many parts of the country, and the Government has committed to doing everything possible to help the recovery.”

Ahead of Wednesday’s budget Mr Osborne announced that a new garden city will be built in the Thames estuary and the Government’s controversial Help to Buy scheme for home purchasers is to be extended until the end of the decade.

The development of a garden city at Ebbsfleet in Kent will initially provide 15,000 homes while the extension of Help to Buy for new properties - which had been due to end in 2016 - to 2020 will support the building of 120,000 additional homes, he said.

Mr Osborne signalled that Tories - like Bury St Edmunds MP David Ruffley and former chancellors Lord Lamont and Lord Lawson - who have been pressing for him to reverse the increasing numbers of middle earners being caught by the higher 40p rate of tax would be disappointed.

The Chancellor said that it was still his priority to lift more people out of taxation altogether through raising the personal allowance - which is widely expected to see a further rise to £10,500 in the Budget on Wednesday.

He made clear his irritation at Liberal Democrat attempts to claim the credit for the policy, which he said had been fully supported by the Conservatives in the coalition, and which benefited those on middle incomes and well as those at the bottom of the income scale.

“My priority has been to increase the personal allowance. That is what I have done in budget after budget. What that means is, yes, you are taking the low paid out of tax - which has been a long-standing Conservative ambition - but you are also helping those on middle incomes,” he said.

“It is only people right at the top, people on incomes of over £100,000 who don’t get the benefit. I think it is a very effective instrument for making sure that hard-working people keep more of their money and I am very proud to be part of a Government that has delivered that.”

• Suffolk Coastal MP Therese Coffey has called on the Chancellor to give bingo clubs a boost by reducing the tax paid by clubs to 15% – like many other forms of gambling.

• Follow our live Budget coverage here from midday Wednesday.