Doncaster MP Ed Miliband was forced to apologise and left stunned - after a caller to his Radio 2 show revealed his toilet habits in great detail.
The former Labour leader, who is spending a week standing in for Jeremy Vine on his BBC show, was hosting a discussion about modern dual-flush toilets compared to tradititonal Victorian loos when caller Jim Doyle left more than seven million listeners stunned with his comments.
Telling listeners how he was no fan of the new style toilets he said: "I don't know how politely to put it, but when you have a big job, it takes three or four flushes to flush it away.
"Then you are left with skid marks down the bottom and you have to get the brush out."
A clearly embarrassed Ed stepped in and announced: "Apologies to anyone eating their lunch," to laughter from Jim.
But the caller was undeterred and continued telling Mr Miliband how a toilet engineer had been called to his home to try and rectify the problem.
"He put 14 bits of paper down the toilet and flushed it away and told me there wasn't a problem.
"I told him 14 bits of paper didn't weigh the same as....you know what I'm trying to say," at which point the Doncaster North MP chipped in "we get your drift."
But in full flow, Jim continued and added: "When you go, it hits the water. Its got a depth to drop into" with Ed again interjecting, "we get your drift."
Wrapping up the call, Jim announced: "It does not save water at all."
Mr Miliband replied: "Thanks for sharing in so much detail your experiences" before quickly playing 90s hit If Only I Could by Sydney Youngblood.
He is standing in on the popular two hour lunchtime show this week, with Conservative Iain Duncan Smith set to take to the decks next week.
Yesteday, he dropped a clanger by announcing the next record as being by The Verve - and then Queen's Radio Gaga kicked in instead.