Brown in 'crony' row over our man in Africa

His decision to appoint Jack McConnell - the former first minister toppled by the SNP in May's Scottish elections - as High Commissioner to Malawi led to claims that No 10 was treating the post as a "political bauble".

MPs and union leaders also claimed the move represented a "worrying trend" in political appointments to diplomatic posts.

The senior civil servants' union, which rarely criticises the Government, complained that the job in Lilongwe had not been open to competition among experienced diplomats.

Paul Whiteman, of the First Division Association, said: "We have assiduously campaigned for appointments to be made on the basis of merit following a process of open competition. This is the only way to avoid accusations of cronyism."

Mr McConnell's nomination followed the appointments of former Scottish secretary Helen Liddell and former chief secretary to the Treasury Paul Boateng to similar posts.

Both had been sacked from Cabinet but ended up in charge of British embassies in, respectively, Australia and South Africa.

Andrew Mitchell, the Conservative's international development spokesman, said Mr McConnell would have been competing against people of "exceptionally high calibre" for the post.

He said: "He has got to be able to demonstrate in a way that faces public scrutiny that he is their equal and is able to do just as good a job.

"I think it is important that the process should be very much in accordance with the norms of public scrutiny."

The Tories also questioned whether offering Mr McConnell the job was an incentive to encourage him to stand down as Labour's Scottish leader.

His replacement is tipped to be Wendy Alexander - a friend of Mr Brown and sister of International Development Secretary Douglas Alexander.

Mr Brown said he offered Mr McConnell the job, which he will start in 2009, as reward for strengthening ties between Scotland and Malawi.

Under Mr McConnell's leadership, the Scottish Executive gave millions to health and educational projects in the impoverished nation. When he visited Malawi two years ago he was ordained with the powers of an African chief, symbolised by a carved mahogany "stick of authority".

A Foreign Office spokesman said previous governments had made similar appointments.

He added: "Mr McConnell has extensive experience both of development work and of the challenges facing Malawi.

"These unique skills - and this track record - will enable him to make an outstanding High Commissioner."

Britain gives more than £ 60million a year in aid to Malawi.