When Channel 5 goes live in three weeks' time, comedian Jack Docherty will host a special launch edition of its flagship talk show on opening night. The Jack Docherty Show is to be closely based on David Letterman's US prototype and will go out every weekday night at 11pm. "Let the Chat Wars commence," cries Mr Docherty. He pledges to destroy Carol Smillie's cosy BBC show.
His closest rival could turn out to be a satellite signing: Sky One's Selina Scott, who last week launched her own topical show in exactly the same late- night slot.
Back on earth, Channel 5's weekend host, Mariella Frostrup, will soon be trying to monopolise Sunday-morning ratings with an arts chat show called Brunch. At the BBC, during the seasonal absence of its current heavyweight, Clive Anderson, and in the wake of the comedian Frank Skinner's first stab at the format, Auntie is hitting back with a new series of Mrs Merton's Bafta-nominated show.
But where will all their guests come from? Even if the shows' "bookers", whose job it is to secure celebrity appearances, keep tabs on literary launches and film premieres, home-grown celebrity offers slim pickings. According to Alan Marke, the independent producer who brought Jonathan Ross and The Last Resort to the screens in 1987, the result will be the increasing Americanisation of our output.
"These new shows are going to have to take anyone and everyone," he said. "It is all about filling up airtime and there is going to be a lot of it for a long time to come because it's cheap. There will be such competition for guests that it will become more and more like American programming."
Mr Marke and his company, Channel X, have just put together an anniversary compilation of the best of The Last Resort and, while he admits that he and Ross stole their format wholesale from Letterman, he disdains shows which are doing the same thing 10 years on.
"Chris Evan's TFI Friday is completely lifted from Letterman. I know all TV is derivative, but it is a bit bad that they are doing it now, when the real Letterman is on Sky Two anyway."
Vincent Beasley, who will produce Channel 5's new show, counters by saying he is "quite unashamed" about the Letterman influence. "There is a resurgence of the chat format now. The trouble is that most of the shows are not paying enough to get exclusivity, so the power is shifting to the agents."
ITV, he notes, can still afford to blaze away with its two big guns, Des O'Connor and Clive James. The secret of O'Connor's success in repeatedly drawing the big names is a combination of docility, wealth and flexibility. The show will often record interviews for the same show on different days.
"Des O'Connor's show sets the top level for payment because they have a lot of cash to splash about. Clive James has clout too, but it is still difficult for him to book Hollywood stars unless they appear on a satellite link," says Mr Beasley. Gimmicks seem to be the only inexpensive way of freshening up the format. The Saturday night gap on Channel 4, once occupied by Gaby Roslin, is now filled by stand-up comic Bob Mills with a show which exposes the behind-the-scenes battle for guests.
"We have had to revise the rules on our A,B and C guest lists now," admits Mills. "In the days of Parky and Russell Harty it was a buyers' market. It is now very much the sellers', or guests', market."