The sale of coalfields has been dubbed "Coalgate" by the opposition.

BBC: India parliament remains stalled over coal scandal

One deterrent for foreign investors has been what is referred to as the Coalgate scandal: allegations of possible corruption over the allocation of coal deposits to companies and the public sector.

BBC: Does India have the will to reform its economy?

The series of scandals - Commonwealth Games, telecoms spectrum, 'Coalgate' - that he has failed to prevent, detect or take prompt action over have massively damaged his party and his government and irretrievably dented his own reputation.

BBC: Manmohan Singh at 80