A Scottish MP is intensifying his campaign at Westminster to end the exploitation of workers on so-called unpaid “trial shifts”.

As the UK begins its busiest shopping period, Stewart McDonald, who represents Glasgow South, insisted the UK Government could no longer turn a blind eye to the “blight” of unpaid trial shifts.

The SNP MP has put forward a Private Members’ Bill to bring to an end to what he says is the common practice of employers offering unpaid shifts to people looking for work with no guarantee of pay at the end of them.

He pointed out how a study this year by Middlesex University and the Trust for London estimated that workers were missing out on as much as £1.2 billion in wages - with unpaid trial shifts contributing towards the figure.

“Unpaid trial shifts are common practice across the UK. However, they are also exploitative and take unfair advantage of people genuinely seeking work.

“On Black Friday, one of the busiest shopping days on the calendar, it is increasingly likely you’ll be served in a shop by someone working an unpaid trial shift.

“The run-up to Christmas is also a time when employers are more likely to take advantage of people genuinely seeking work.”

He said his Private Member’s Bill – which will only become law if supported by the UK Government - has already received widespread support from the likes of the Scottish Trade Union Congress, the National Union of Students and the Better than Zero campaign.

“It’s time this Tory Government and parties across the UK also stepped up to the mark. A fair day’s work deserves a fair day’s pay. All work should be paid fairly and properly, which is why the practice of exploitative, unpaid trial shifts must come to a long overdue end,” added the MP.