Henry Bellingham said he has always believed MPs should have outside interests as he came under fire for taking a job as chairman of a mining company. The North-West Norfolk MP, who was minister for Africa in the foreign office until 2012, said his new role at Pathfinder Minerals was a very small commitment and would not have an impact on parliamentary or constituency work.

He has come under fire from political opponents and campaigning groups which claim that it 'corrodes trust in politics'.

Mr Bellingham met Pathfinder Mineral, the company of which he is now chairman, over a licence dispute in Mozambique while a minister. In a 2012 trading statement the company said the Norfolk MP would continue to take a close personal interest in the issue.

In a statement to the stockmarket, Mr Bellingham said: 'I share my fellow directors' aim to restore control to Pathfinder of the heavy mineral sand deposits in Zambezia Province acquired by Pathfinder in 2011; and to develop them for the benefit of Mozambique and of Pathfinder's shareholders.'

Mr Bellingham told the EDP there was a 'rigorous' process to go through before a former minister was able to take on an outside interest and the Cabinet Office had approved his application.

He said: 'All appointments to former ministers and former civil servants have to be cleared by a highly rigorous process. They actually had this application for a number of months and they are satisfied.'

He added: 'It is a very small company. It employs four people and its value is under £2m. It is obviously going to be a very small commitment. I have always believed that MPs should have outside interests.'

The Norfolk MP also lists directorships at consultancy and conference organiser Developing Markets Associates Ltd and fishing firm Pontus Marine Ltd and is also an unremunerated director of Global Law Summit Ltd, which is behind commemorations of the 800th anniversary of the Magna Carta.

He is trained barrister who is no longer practising.

Mr Bellingham said: 'I have always taken the view the MPs should have outside interests and you have to balance those against your constituency interests, which always come first. Everyone is entitled to some time off. I work ten hours a day, sometimes up to 15, and if I want to spend some time on outside interests, that is my judgement call.'

Alexandra Runswick, director of the pro-transparency Unlock Democracy campaign, said: 'The revolving door whereby former ministers take paid employment with companies they were involved with in their government role corrodes trust in politics.

'Politicians have a privileged position and this should be used for public service not developing a future business career.'