A parliamentary committee has written to Norwich MP and Treasury minister Chloe Smith demanding she answer questions on the government's plans for green technology.

The development of low carbon technology for energy production – like power stations that generate electricity from wind and biomass – forms a key part of the so called 'green economy'; business opportunities arising from the country becoming more environmentally friendly.

The green economy is thought to be worth some �112bn to the UK, a figure that will jump by 45pc in the next two years. Meanwhile, the New Anglia LEP, a Norfolk and Suffolk business organisation, wants 25pc of that growth in the Eastern region.

Currently, the state provides subsidies to encourage the development of low carbon technology, but ministers plan to introduce a cap on such payments; a move which some businesses say will stymie growth.

As a result, the energy and climate change select committee is investigating the cap, but has so far failed to convince a Treasury minister to attend a hearing to explain the policy.

The committee chairman Tim Yeo said: 'The Treasury is being disingenuous in arguing that it would not be right to comment on the Department of Energy and Climate Change's new legislation.

'The success of electricity market reform could well rest on Treasury decisions – such as how high to set the levy-cap on support for low-carbon technology.'

He added: 'The minister must not duck these vital questions.'