Tapol (the Indonesian Human Rights Campaign), the Campaign Against Arms Trade and the World Development Movement have photographic and video evidence they say proves that the British Government is breaking its own policies on arms export and human rights by giving the go-ahead to the exports - including a licence covering more than 300 armoured vehicles made by Southampton-based Glover Webb.
A letter last month from the organisations' solicitor, Stephen Grosz, to Mr Lang highlighted an incident in April last year when the Indonesian army used British-made armoured vehicles to disperse a demonstration. Three students were killed.
The organisations gave Mr Lang a month to avoid the prospect of legal action by agreeing to withdraw the licences. The deadline expired at 5pm yesterday.