Rangers boss Mark Warburton sees place for Old Firm in English football

“I think that [British league] could be possible”, he added.

Despite a 100 percent start to their league campaign, Warburton says he is still warning his players about complacency.

English clubs voted against that proposal in 2009 but the Irish businessman Desmond, who once held a stake in Manchester United, thinks it is an “inevitable” outcome eventually.

The levels of finance available to Rangers and Celtic are dwarfed by even lower ranking Premier League outfits as they are overshadowed in terms of transfer fees and wages.

“Then we made a stupid mistake – as happens in football – but you get punished hard when you are in Europe”.

Since then, Scottish football has suffered from Rangers being demoted to the bottom division in 2012 after a financial crisis, losing their regular fixtures against Celtic with a consequent decrease in gate money and television receipts.

The TV deal struck earlier this year is set to kick in next year and will run for three seasons as the money in the Premier League continues to escalate.

“It takes time but I think Celtic is a team that should be playing the best and have an opportunity to be playing in the best league”.

A move down south for the Old Firm has been talked about historically, and earlier this week Celtic shareholder Dermot Desmond said that he expects the clubs to join the Premier League within the next 10 years.

“In Italy and in Spain you have the bigger clubs like Barcelona and Real Madrid who negotiate their own football contracts, because they are more advantageous to them”, he said in a separate interview with STV.

Rangers are looking to extend their lead at the top of the Championship this weekend when they take on second placed Falkirk at Ibrox.

“I think there will be different types of negotiations between teams and leagues that will evolve into more competitive leagues in the British Isles”, said Desmond.

Deila concedes that failing to overcome Malmo in the Champions League play-off round was a major disappointment, but insists he has had no doubts over his overall blueprint for the club.