Gavin Laird, general secretary of the Amalgamated Engineering and Electrical Union, argues that the Democratic Party in the US is a possible model for Labour to follow.
While the AEEU has argued in favour of John Smith's version of one member, one vote in the Labour Party, it has not so far contemplated a constitution in which unions play no part whatsoever. Until now the union has not argued against a union presence on the party's national executive, for instance.
Writing in the union's August journal, Mr Laird points out that since President Clinton came to power in the US, unions' popularity has improved 'dramatically' and non-union members have begun to 'wake up' to the benefits of union membership.
Mr Laird says that a study by the Wilson Centre for Public Research in the US shows that there are so many workplaces ripe for organising that unions would not have the resources to keep pace with demand.
'Our experience in recruiting bears out what the American unions are saying. If the lessons are learned, there is every reason to believe that we can for the first time in two decades actually reverse the decline in union membership.'
In the US unions were beginning to 'reap the rewards' of the Clinton presidency. 'Unlike the UK there are no formal links between the Democratic Party and the unions, yet already measures have been taken to reverse the anti-union legislation of the Reagan era.
'Perhaps there is a lesson here for some of my union leader colleagues who seem hell bent on destroying any possibility of the British public electing a Labour government.'
The AEEU contends that Labour's close identification with unions contributed heavily to defeat in the last election.
Unions command 70 per cent of the vote at Labour's annual policy-making conferences and are currently engaged in a series of private negotiations over the relationship between the two wings of the movement. The AEEU is the only big affiliate so far to back publicly John Smith's plan for a reduction in union influence.
Mr Laird conceded that his own union had lost 9 per cent of its members over the last year as manufacturing continued to decline.
A recent Gallup poll in the US, however, showed that 73 per cent of the American people thought unions were necessary.