MPs have expressed "dismay" at the prime minister's decision to appoint John Reid to one of the most sensitive jobs in government.

Lib Dem MP Paul Tyler said the former party chairman would need a rapid change in style if he is to prove he can discharge his duties to the House.

"MPs of all parties will react with dismay to the announcement that John Reid is to take the place of Robin Cook," said Tyler.

"Mr Reid will have to make the mental switch from imposing the will of a party dictatorship to promoting the merits of Parliamentary democracy. He has a reputation as 'King of the Control Freaks' to live down.

"Mr Reid will have to adopt a completely different attitude if he is to continue the consensual approach to parliamentary business achieved by Mr Cook.

"After the biggest ever backbench rebellion, over Iraq, this was an opportunity for the prime minister to show that he cares about listening to the Commons.

"Unless Mr Reid now changes his style dramatically the gulf between government and parliament may widen to perilous proportions."

Labour backbencher Graham Allen said he hoped the new leader of the house will see parliament as "a partner...rather than as a political problem to be contained".

"The most sophisticated political prison in the world has either been given a new governor or a liberator. Time will tell which," he said.