Democrats kept in suspense while Kerry decides on his running mate

John Kerry, the Democratic challenger for the White House, is close to the announcement of his vice-presidential running mate, possibly in time for the pair to appear at a major New York fundraiser on Thursday.

John Kerry, the Democratic challenger for the White House, is close to the announcement of his vice-presidential running mate, possibly in time for the pair to appear at a major New York fundraiser on Thursday.

Even by the traditionally secretive standards of the vice-presidential selection process, this has been an exceptionally leak-proof operation, with no sign that any of the touted candidates has established a decisive advantage.

But with the Democratic nominating convention in Boston barely three weeks away, the moment of choice cannot much longer be put off. In a sign the decision may be imminent, Bill Richardson, the governor of New Mexico and widely mentioned as a dark horse candidate, publicly took himself out of the running on Thursday, citing his promise to voters in his state to serve out his full term as governor. The announcement followed a two-hour meeting between Mr Kerry and Mr Richardson.

The withdrawal of Mr Richardson, whose biggest attraction was his popularity in the important Hispanic constituency, leaves three contenders at the top of every analyst's shortlist: the North Carolina senator John Edwards, the former Democratic House leader Richard Gephardt, and Tom Vilsack, the highly regarded governor of Iowa.

If rank-and-file Democrats had a say in the matter, Mr Edwards would be the strong favourite. His personal magnetism was evident on the campaign trail, where he was the last serious challenger to the Massachusetts senator, and many senior Democrats have urged Mr Kerry both in public and in private to pick him.

Though Mr Edwards would probably not enable Mr Kerry to carry any states in the South, which the Bush-Cheney ticket swept in 2000, he has national appeal, and generates buzz and excitement in a manner the sometimes dour and ponderous Mr Kerry rarely matches.

The problem lies in the personal relationship between the two men - civilised enough, but nowhere near as easy as that between Mr Kerry and Mr Gephardt. The challenger may also fear that the campaigning skills of the fluent Mr Edwards will make his own efforts seem embarrassingly cumbersome.

Mr Gephardt by contrast is probably the closest of the three to Mr Kerry. At 63, he is considered too old to have subsequent presidential ambitions of his own. A veteran of two White House campaigns in his own right, and with 28 years in Congress, he has huge Washington experience and strong ties to the core Democratic constituency of organised labour.

An added possible bonus is Mr Gephardt's native Missouri, a vital battleground state which Mr Bush narrowly won four years ago, and which only once in the past century has not voted with the winner in a presidential election. His drawback however is that he is an overfamiliar figure, who would add little excitement to the Democratic ticket. A third option is Mr Vilsack, a rising star among Democratic governors who personally gets on very well with Mr Kerry, and who could ensure that the Democrats carry his home state of Iowa, which Al Gore won by barely 4,000 votes, less than 1 per cent, in 2000.

This weekend Mr Kerry is scheduled to make a bus tour of several key mid-Western states, before spending Monday at his wife's farm near Pittsburgh. It is then that he may make the final decision, a report in his home town paper, The Boston Globe, said this week.