THERE was once a time not so long ago that David Cameron liked television debates.

So much so that he challenged Gordon Brown to one.

He said they were informative and interesting, bringing politics to life.

That was in 2008 when he was opposition leader and he wrote to the then Prime Minister to go before the cameras.

At that time it was Mr Brown who was less keen on the idea.

Since then Mr Cameron has changed his tune on the big set piece leader's debate.

The Prime Minister has the most to lose in a televised debate that's why he doesn't want one. And he will only do it if the seven party leaders are included.

That would mean Tory, Labour, LibDem, SNP, Green, Ukip and Plaid Cymru included but Respect, DUP, Sinn Fein, SDLP and Alliance, who have MPs, out in the cold.

Either way you will need quite a wide screen telly to fit the lot on your screen.

After Nigel Farage was to be included in one of the planned debates Mr Cameron has said the Greens needed to be included if Ukip were involved. So the other parties had a legitimate claim to being included too.

Now he says he will do only one and has ruled out a head to head with Ed Miliband.

Again, a change of tune from 2008 when he was the challenger.

He wrote to Mr Brown about engaging young people in politics: "I have long believed that a television debate between the main party leaders would be an excellent way to achieve that."

He also wrote: "I remain ready to hold such a debate, either between the two of us, or including the Liberal Democrats, whenever the opportunity arises."

It is another example of a politician saying one thing in opposition than another once in power.

Mr Cameron knows he has most to lose whether it is in a straight head to head with the Labour leader or with the others.

If his stated position had always been I don't like Television debates, they bring nothing to the democratic process then it would be acceptable.

The Prime Minister cannot be allowed to pick and chose if he will or will not debate on television and then get to decide who else in included.

It is obvious he is trying to sabotage any plans for the event to take place and if so make it as wide as possible to ensure damage limitation.

What it all shows is the UK parliamentary system is not suited to leaders' debates.

It is not the USA where the choice is two people for president. If there is to be election debates it should be between parties and their policies and not personalities.

For decades the television companies have been trying to get US style leaders' debates on our screens to grill the politicians.

They have ended up with David Cameron running rings around them.