The Tories are finally getting their own back for the ‘Thatcher, Thatcher milk snatcher’ jibe – by shopping a Labour MP for drinking it during a Commons debate.

Tory frontbenchers spotted new boy Steve Witherden taking a swig from a milk carton last week and tipped off the Deputy Speaker.

The incident – dubbed ‘Milkgate’ – led to a quiet rebuke for the Welsh MP and a reminder of the strict ‘no food or drink’ rules when in the Commons chamber.

It comes more than 50 years after the then education secretary Margaret Thatcher was given her ‘milk snatcher’ label when she ended free milk in schools for the over-sevens.

Last night, Mr Witherden – who won his Montgomeryshire and Glyndwr seat in July – was apologetic, saying that he was still learning the rules of Westminster.

Tory frontbenchers spotted new boy Steve Witherden taking a swig from a milk carton last week

The incident – dubbed ‘Milkgate’ – led to a quiet rebuke for the Welsh MP and a reminder of the strict ‘no food or drink’ rules when in the Commons

But in a swipe at his accusers, the MP’s spokesman said he would not be ‘ashamed of supporting British dairy farmers considering how badly they were let down by the last government’.

Fortunately for Mr Witherden, Commons cameras failed to pick up the moment he took a swig.

But they did record Deputy Speaker Nusrat Ghani speaking to Labour Whip Anna Turley, who then spoke privately to Mr Witherden. Moments later, he was no longer in his seat.

The episode has earned him the nickname ‘Ernie’ in Westminster, after Benny Hill’s ‘fastest milkman in the West’.

In a traditional exception to the chamber’s food and drink rule, Chancellor Rachel Reeves will be allowed a drink of her choice as she delivers this week’s Budget.

However, sources close to Ms Reeves said last night she would be drinking water, not milk.