The question over how much MPs splash out on first-class train travel constantly crops up in written parliamentary questions.
Shadow communities secretary Andrew Gwynne was the latest to have a go at Sajid Javid's team, asking how much his ministry had spent on first-class train tickets in the last four years.
Northern Powerhouse minister Jake Berry was quick to point out that his department's expenditure on first-class train tickets had fallen by 97%.
He may have also chosen to point out that Mr Gwynne himself – perhaps hypocritically - has shown a preference for travelling in style, making 64 claims for first-class tickets worth £4,849.30 and just three for Standard-class in 2016/17.
Asked about his use of first-class by a local paper, Mr Gwynne's office said: 'We purchase the cheapest ticket of any kind on offer online at that time.
'Mr Gwynne only uses rail to travel between London and Manchester and has never used the more expensive option of driving to and from the capital for Parliamentary business.'
If Mr Gwynne is so familiar with the benefits of first-class travel, Diary wonders why he asked the question?
