Hundreds of thousands of small retail businesses will benefit from tax breaks worth £300 million in a long-term economic plan to revitalise local economies.

The Government has also earmarked £100m to support major infrastructure projects in key Enterprise Zone business areas, and a further £15m to help develop business spaces at universities in eight major English cities.

The funding was announced today by Communities Secretary Eric Pickles, who promised £415m to back businesses, boost high streets and create jobs.

It comes after a £1 billion package was announced in December to support British hight street businesses.

The new money will give 300,000 small retail firms a discount of £1,000 off their next tax bill, which will be automatically included in business rate bills sent out by councils.

Some 66,000 shops in London and 46,000 in the North West will be among those eligible for the £1,000 discounts, available in 2014/15 and 2015/16.

Businesses such as payday lenders, betting shops and pawn brokers will be excluded from the offer, which can be used on top of other previously announced measures that come in to effect in April to reduce the tax burden on small firms.

The measures amount to the largest package of support in over 20 years, the Department for Communities and Local Government said.

Twelve bids by Enterprise Zones - areas that support new and expanding businesses by offering incentives - have also been shortlisted for a share of £100m to regenerate dormant sites into prime economic land.

The funding will see 3.5 million square metres of land brought back into use, the building of new roads and bridges to increase access, new commercial premises and the creation of up to 3,000 jobs in key industries by 2015.

Money for projects at Enterprise Zones in Harlow, Humber, Leeds, Sheffield, Discovery Park in Kent, Oxford, Daresbury, Alconbury, London's Royal Docks, the Black Country, Nottingham and the Solent has been agreed in principle.

Among these are a £15m project at the Humber Enterprise Zone. The Humber Energy Estuary is set to become the centre of the global offshore wind industry, and the funding will speed up delivery of key infrastructure at Able Marine Energy Park, enabling the zone to create a "renewable energy super cluster" which will bring 4,100 jobs by 2020.

The £415m funding pot also includes £15m to establish new university Enterprise Zones in eight major cities - Birmingham, Bristol, Leeds, Liverpool, Manchester, Newcastle, Nottingham and Sheffield.

The university zones will strengthen the role of higher education in supporting local growth and innovation, and will lead to the development of new business spaces which will host a range of start-up, high-tech companies that can benefit from universities' expert knowledge.

Unveiling the funding, Mr Pickles said: "As part of our long term economic plan, we are backing business and enterprise right across the country, helping town centres and local industries to prosper, and building a stronger economy.

"This money for infrastructure will transform acres of Enterprise Zone land and build a stronger, more competitive business environment that will create up to 3,000 jobs for hard-working people across the country.

"While our fully-funded £1,000 retail discount will make a huge difference to 300,000 of the essential small shops and local traders we find in our town centres across the country."