SUPERMARKET CHAIN TESCO has come under fire for trying to sway the results of this year’s X Factor series, which features one of its Irish workers as a contestant.

The chain sent a circular email to each of its 300,000 staff in the UK and Ireland, asking them to vote for contestant Mary Byrne (50), who works for the supermarket as a checkout assistant in Ballyfermot.

It also paid for a high-profile advertisement on TV3, aired just after her performance on Saturday’s show, wishing her the best of luck in the competition.

The kind-hearted gesture has been slammed by proponents of the 13 remaining contestants, however, who complain that the supermarket giant is attempting to “fix” the show.

A Tesco spokesman, when contacted by the Daily Mirror, said the chain was merely “fully supportive of Mary and so are her friends and colleagues at Tesco – but as to how anyone votes, that is up to them.” A TV3 spokesman added that neither the channel or Tesco had broken any rules.

Byrne (50) sailed through Saturday’s first live show, but suffers from arthritis in her right knee and is currently resting up ahead of this weekend’s shows.

In separate X Factor developments, controversial singer Katie Waissel has reportedly threatened to quit the show in response to an internet hate campaign complaining that she was included in the show instead of popular Zimbabwean singer Gamu Nhengu.

Waissel was given permission to visit her family yesterday in an attempt to boost her spirits and restore some of her confidence, which is in short supply after she finished in the bottom there and was only saved by the judges.

Waissel is considered the bookies’ favourite to be dropped from the show this weekend.