This Morning's Phillip and Fern collapse in helpless giggles for SIX minutes live on TV

But This Morning hosts Fern Britton and Phillip Schofield surpassed themselves yesterday, dissolving into giggles live on air for a total of six minutes - and all because of Jeremy Paxman's pants.

The trouble began after Miss Britton, 50, apologised to viewers of the ITV1 show for a slight lisp caused by having a tooth out.

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Phil and Fern are unable to contain themselves as a combination of Fern's lisp and Jeremy Paxman's pants reduce them to helpless laughter

"I'm sounding a little silly today because I had a tooth out at the back on Friday," she said. "I even managed to whistle earlier by mistake."

Schofield, 45, then mocked her lisp, causing the two to wheeze with laughter.

They then moved on to discuss Paxman's complaints about the alleged poor quality of Marks & Spencer underwear.

Miss Britton said: "It's a miserable day for Jeremy Paxman because his pants don't fit."

The pair collapsed again after a mocked-up picture of the Newsnight host wearing a pair of pants was flashed on screen.

As Miss Britton said: "Do you feel like a pant rant?", Schofield made lunging movements as though to demonstrate the merits of his own underwear.

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Going, going... gone: Phil and Fern erupt in fits of giggles as they try to introduce the programme

Miss Britton continued: "What makes a good pant? You want to feel the undercarriage is secure and snug. You don't want them wobbling around."

Schofield replied: "Yes, yes, undercarriage stowed." His co-host then retorted "Flaps up!" before both collapsed in hysterics.

They calmed down in time to introduce a clip of a production of The Wizard Of Oz with the characters played by dogs in costume, but the sight only sent them off again.

Finally, after Miss Britton stumbled over introducing Boy George, Schofield managed to get a grip.

"This was a mistake from the moment we both walked in today," he said. "We have already got the award for the longest opening menu of the show!"

An extract from the pair's 'pant conversation':

Fern: "Do you feel like a pant rant? Because we might do pants tomorrow."

Phillip: "I think we should do a test of all sorts of different pants. Like that (jumps up and down, lunges)."

Fern: "Oh I like that."

Phillip: "Currently I'm very happy with my pants."

Fern: "Are you comfy with your pants?"

Phillip: "Yes, I'm happy with my pants."

Fern: "Because what makes a good pant? You want to feel the undercarriage is secure and snug. You don't want them wobbling around."

Phillip: "Yes, yes, undercarriage stowed."

Fern: "Flaps up!"

(Both collapse in hysterics)

Phillip: "Not down"

Fern: "No."

Phillip: "Cos the last thing you want is your undercarriage ripped off."

Fern: "At speed."