Six Nations chiefs have been warned they could face a backlash from sponsors if they take the Championship away from terrestrial television and behind a paywall under a new £300m deal with Sky.

Guinness have a six year deal worth an estimated £50m to the Six Nations which runs until 2024 and exposure on terrestrial television – the BBC and ITV currently share rights – would have been a major selling point. Although a switch to a paywall channel would theoretically allow for more sponsors’ mentions, the audience will be much smaller compared to the 12.8m who tuned into the Rugby World Cup final between England and South Africa on terrestrial television last year.

Following the departure of RBS, Guinness, it is understood, are paying around £6m for the first year – a figure which will grow to double that by 2024.

Faced with this scenario, a Six Nations insider told RugbyPass that a new television deal could be structured similarly to Premier League football with various packages of matches sold to the highest bidder. He explained: “ If, for example, Sky put forward the biggest bid then their package could revolve around first choice of match and kick off time for each round of the Championship which would almost certainly be the one involving England. There would, under that system, be the ability to offer a limited package to a terrestrial channel. That would head off some of the criticism from those who do not want to pay to watch Six Nations games on TV.”

There has been, as expected, considerable anger on social media at the possibility of the Six Nations being put behind a paywall if a deal involving Sky, BT or Amazon is struck and Nigel Currie, industry expert and former joint chairman of the European Sponsorship Association, believes sponsors with existing deals will be closely watching developments. Besides Guinness as the headline sponsor, the Six Nations has deals with Amazon Web Services and Tissot.

Currie explained: “ If Guinness have a good sponsorship deal, which I suspect they have given there were not that many companies bidding to take over the Six Nations, they would have a case to revisit the details of the deal. While Sky audiences are growing, they are no where near the biggest terrestrial audiences. The Guinness deal would have been done on the basis it was on terrestrial channels. The Six Nations may have had some protection in the agreement but you would expect the sponsorship money to be dependent on the television deal.

“Guinness are a big, canny operator and this is a big sponsorship deal and it would have been water tight. If goes onto Sky they may be able to offer sponsors more in terms of break bumpers and exposure because it’s a commercial channel. However, terrestrial television picks up millions of viewers who may like a bit of rugby but they would not be prepared to pay for the privilege.“