Norwich South MP and ex-soldier Clive Lewis has revealed he nearly shot at a civilian while on tour in Afghanistan.

The shadow defence secretary, who suffered depression after returning from his three-month tour, admitted the incident while criticising law firms for hounding soldiers over their roles in Iraq.

The Labour MP said if troops are left uncertain about what support they will have from the armed forces over 'an accident', it could impact on the effectiveness of combat.

Speaking at a fringe event at the Labour Party conference in Liverpool, he said: 'The key thing is our soldiers should be able to deploy and know that they have the support to be able to make decisions in the best interest of their forces on the ground.

'I can speak from knowledge here, from personal experience.

'When I was in Afghanistan there were situations - and I can think of a situation in particular - where I could have easily shot a civilian.

'It could have happened. Very close.

'And I needed to know - I was given the reassurance that as long as I had followed certain rules and procedures, I knew that I would be protected by the state, by the armed forces.

'I wouldn't be hounded for what was in effect an accident under very strenuous circumstances.

'If you begin to throw doubt on that and you make people begin to think twice then you basically in effect degrade combat effectiveness and put people in danger.

'There is a balancing act between being able to operate freely and effectively but also to ensure that civilians and others are protected in the appropriate way.'