Andrew Lewis, the IoD chairman, says those who remain should be paid more and is calling for members to put pressure on the government.

It is claimed some representatives find themselves out of their depth.

But Senator Frank Walker says the matter of reducing the number of members has been debated on a number of occasions and voted against.

Senator Walker told BBC News: "The IoD is entitled to its opinion, but the fact of the matter is we are where we are.

"It's been discussed and debated and members voted against a reduction, so it's likely to remain as it is for the foreseeable future."