The arms-to-Africa scandal which deeply embarrassed the government in the summer enters a new phase in the Commons on Tuesday.

Political Correspondent John Kampfner on the key players in the arms-to-Africa saga

The powerful foreign affairs committee of MPs will for the first time cross-examine the two men at the heart of the allegations that weapons were provided illegally to help a counter coup to oust the military junta in Sierra Leone.

They have called Tim Spicer of Sandline International and Britain's High Commissioner Peter Penfold to give evidence on the affair.

But their meeting comes on the same day as Chancellor Gordon Brown's crunch pre-budget statement.

And some in Westminster are claiming that the timing is a happy coincidence for the government as the chancellor's statement will overshadow any further embarrassing remarks in the committee.

Cook cleared

Mr Spicer, whose company provided the arms for the successful operation, will be quizzed over his previous claims that he had Foreign Office approval for the intervention.

Penfold: A national hero

And Sir Peter will be asked to spell out exactly how much he knew of the exercise, and what encouragement he gave it.

An independent inquiry by Sir Thomas Legg cleared Foreign Secretary Robin Cook and officials of any knowledge of the busting of the UN arms embargo.

But it did find that Sir Peter, who is regarded as a hero in Sierra Leone for his actions during the crisis, gave the arms shipment some approval without realising it would be illegal.

Sean Curran: Tim Spicer claims he didn't know arms shipment was illegal

The row also escalated into a constitutional clash between the select committee and the foreign secretary after he refused to hand over documents while the Legg inquiry was sitting.

Fiddle timetable

Some committee members have previously claimed the government was trying to fiddle the parliamentary timetable to limit the embarrassment cause by the affair.

Minister have always denied this and insisted they have acted under previous precedents.