By Wayne Veysey

15th Jun, 2019 | 9:00am

Sources: PL big hitters ambush Celtic with 'seriously big offer'

Celtic’s pursuit of David Turnbull is on the brink of collapse after they were ambushed by a Premier League club believed to be Southampton, Football Insider understands.

The Glasgow giants had a £3million-plus bid accepted for the attacking midfielder by Motherwell on Wednesday and were all set to confirm him as their first summer signing yesterday.

A Celtic source has told Football Insider that an eleventh-hour ambush from south of the border has virtually killed their chances of signing the highly-rated teenager.

The team, believed to be Southampton, have turned the head of Turnbull and his camp with what the source claimed is a “seriously big offer” that exceeds the five-year contract the Glasgow giants had agreed with the player earlier in the week.

There is also strong interest in the rising star from Sheffield Wednesday.

The treble winners took the highly unusual step of releasing a statement yesterday evening to maintain they have made Turnbull a “magnificent” offer, warning him to take it or leave it.

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Privately, Celtic fear their hopes of signing the player are all but dead in the water and they will now have to look at alternative targets.

That will be a crushing blow to manager Neil Lennon, who has urged the club to push through the signing of Turnbull following his breakthrough campaign.

He made a huge impact at ‘Well last season, scoring 16 goals and supplying seven assists from 34 matches and ending with a blaze of goals and dazzling performances.

In other Celtic news, it can be REVEALED that the club are confident of sealing three new signings by the end of the month.