Gordon Brown’s Trade Minister has told businessmen that he will resign before the next election because he is not prepared to support the Prime Minister publicly during the campaign.

The Times has learnt that Lord Jones of Birmingham, the former Director-General of the CBI, has decided that he will step down rather than risk a row that could damage the Government.

Lord Jones, the first British minister to be appointed without being a member of a political party, also risks angering colleagues by suggesting that he finds his duties in the House of Lords frustrating.

He joins a growing list of ministers – including Ivan Lewis, the Health Minister, and Gerry Sutcliffe, the Sports Minister – who have caused difficulties for Mr Brown by speaking out of turn.

Lord Jones’s words will come as a further blow for the Prime Minister’s “Government of all the talents”, after Lord Malloch-Brown, the Foreign Office Minister, criticised the US and Lord West of Spithead questioned the need for extending detention without charge – remarks that he later retracted. A spokesman for UK Trade and Investment said that Lord Jones was in the job only for a “finite period”.

The news comes as Mr Brown flies to Washington for three days to meet President Bush and the three presidential candidates and to attend a session at the UN, leaving behind him unhappy MPs and the worst polls of his premiership.

Lord Jones made the comments at a private meeting on January 29 in Great Smith Street in Westminster. About ten businessmen and lobbyists were present, and The Times has spoken to two people who attended the event.

Asked how long he would remain a minister, Lord Jones said that he would leave well before an election campaign got under way because he did not want to be asked by the media whether he was supporting Mr Brown.

He did not plan to offer his allegiance to any party, but felt that his failure to answer the question would lead the media to suggest that he was abandoning Mr Brown.

His remarks will fuel speculation about his future. Last month David Cameron lavished praise on the controversial minister, saying: “Who knows what party he will end up in?”

Lord Jones was also critical of the Civil Service, saying that its members did not want to do anything controversial or exciting, although he added that the civil servants who supported him directly were exceptional.

He did not directly criticise the Prime Minister, suggesting that he was very happy to have been appointed to the job. However, he repeated his unhappiness at the changes to capital gains tax and to the tax rules for “nondoms”.

He suggested that his role – bringing business investment to Britain — should not be done by a minister but by a leading independent businessman. He believes that politicians are usually poorly placed to head such business-centric organisations. However, his office insisted last night that he was happy with the current arrangement.

As part of the remarks, he revealed tensions between his functions in the House of Lords and his ministerial role on overseas trips. He recalled a discussion that he had with the Whips’ Office in the Lords where it explained that he would have to cut a trip short for a vote, which he resisted. Lord Jones’s office said that he did not recognise the remark about the Whips’ Office and emphasised that the minister thanked the Lords Whips’ Office for its co-operation in this role.

Last night a spokeswoman for UK Trade and Investment said that it was “widely known” that Lord Jones would stand down at some point. She said: “As a dedicated supporter of British business, who has spent years raising business issues from the outside, Lord Jones has said on many occasions how delighted he was to join the Government as Trade and Investment Minister, working as part of a successful team focused on maintaining the stability and competitiveness of the British economy.

“It is no secret that he does not wish to pursue a political career in the long term and he has always said he would continue in his ministerial role for a finite period.

“With a successful 30-year business career behind him and the benefit of a single focus on trade and investment, he will continue to use his ministerial position to deliver more intensive support for UK business internationally and to bang the drum for brand Britain around the world.”

Lord Jones is expected to return to the private sector when he steps down.

According to the Public Whip website he has attended 13 out of 64 votes in the Lords since his appointment, and has not voted since February.

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