AT the time of writing it is unclear whether tonight's TV debate in Mississippi between Barack Obama and John McCain will take place. McCain has proposed that it should be postponed until difficulties over Congressional approval of President Bush's $700 billion rescue plan for the US's stricken financial sector are resolved; Obama has responded by saying that presidential candidates need to be able to focus on more than one problem at a time - tonight's scheduled subject on TV is foreign policy and national security. There must be more than a mild suspicion that Mr McCain's preference for being in Washington and if necessary involving himself in the negotiations over the President's rescue proposals are an attempt to win back some of the ground he has lost in recent days over his erratic reactions to the financial crisis. One of the latest polls gives Obama a 14-point lead over McCain when voters are asked which candidate they would trust more with the economy and also shows the Democrats leading the Republicans among likely voters by 52-43 per cent.

These margins are the first statistically significant leads that either side has had in this campaign and it would be odd - and unprecedented - if McCain chose to duck out of a TV debate on a subject which he considers to be his strongest. On the assumption that he shows up, the 90-minutes debate will be shown live on CNN at 3am local time here and repeated tomorrow morning at 11am.