Earlier on Tuesday he highlighted 'obvious concerns coming out of the proposal'

'will not support' the plans for an overhauled global Test structure

It's understood he has already told the likes of New Zealand and South Africa

The RFU have informed rival unions in the southern hemisphere that they will not sign up for the proposed Nations League - meaning World Rugby's revolutionary proposal is doomed.

Nigel Melville, the interim chief executive at Twickenham, has publicly outlined reasons why the RFU are opposed to the concept.

And Sportsmail understands that, behind the scenes, he has already told officials from Argentina, Australia, New Zealand and South Africa that English rugby's governing body 'will not support' the plans for an overhauled global Test structure.

The RFU have informed rival unions that they will not sign up for the proposed Nations League

Nigel Melville has publicly outlined reasons why the RFU are opposed to the concept

It appears that the RFU are showing solidarity with their counterparts in the other home nations and Italy, in resisting the proposal which would involve a system of promotion and relegation being introduced in the Six Nations.

The leading European unions are due to take part in a conference call on Friday with World Rugby and In Front - the Swiss-based sports marketing agency ready to financially support the Nations League - but they appear to be going through the motions.

However, the RFU remain adamant that they have not yet adopted a firm position and that no definitive policy has been communicated to officials elsewhere. In response to Sportsmail's story, a union spokeswoman insisted that the board would formally debate the matter today before a decision is made about whether or not to support the World Rugby blueprint.

At a meeting convened by World Rugby in Dublin earlier this month, unions were informed they had until March 29 to sign up to the Nations League en masse, or it would not go ahead.

That deadline has since been extended to April 5 - next Friday. It is thought that the SANZAAR contingent will all officially confirm their support later this week, but there is a north-south divide on the issue which means the three-division concept will not be taken forward.

It appears that the RFU are showing solidarity with the other home nations, France and Italy

Instead, the Six Nations unions are expected to press on with their own plans, known as Project Light, involving a lucrative new rights deal covering the annual championship, wrapped in with the autumn Test programme in Europe.

There are competing offers on the table, including one from CVC, the private equity firm which has already bought a stake in the Premiership. Sportsmail has been told that a new deal may involve Amazon obtaining rights.

Earlier on Tuesday, Melville presented the RFU's official, public stance regarding the Nations League vision being championed by World Rugby, saying: 'The narrative makes sense, but there are obvious concerns coming out of the proposal.

'If you take them in order, player welfare is a significant one. We have to look at the July window. You could end up playing South Africa, Argentina and Japan, which I think was the proposal for 2026, which would be a difficult one. I don't think anyone fancies that holiday.

Earlier on Tuesday, Melville claimed: 'There are obvious concerns coming out of the proposal'

'The other one is in a Lions year you'd have two games against Japan and Fiji. That's probably fine. Or on a normal year we may play Japan, Australia and New Zealand.

'Some of them work, some of them don't. From a player welfare perspective, is it fair to ask players to jump on a plane straight after a hard season and ask them to play three games? We usually stay in one country or two countries close together. To go to three is bit of a challenge.'

Addressing the subject which has proved especially divisive, Melville went on: 'The second point is promotion and relegation. I don't think anyone is against the principles of it.

'In order to make it work Six Nations-wise, you need a credible tier two tournament. I don't know what you'd be relegated into at the moment. That tier two tournament is something we've got to build, World Rugby has a responsibility to build that.

'For us, being relegated would be catastrophic, commercially. The catastrophe isn't just the team being relegated, it's our ability to fund the game as a governing body in England. Can we fund the community game in England to the level we do now if we don't have the revenues we have?

World Rugby chief Sir Bill Beaumont had been determined to oversee a consensus agreement

There is understood to be support for Agustin Pichot to take over the chairmanship next May

'In the model, there's no promotion and relegation on a Lions year and there's no tournament in a World Cup year. So when you're relegated, you're relegated for two years, not one. It's not quite up and down, one season on the naughty step and go back up, it's actually two years and that could be a disaster for people.

'The other issue is Regulation 9 (governing player release) weekends. The new proposed tournament needs another week for the final (each autumn) and I think that might throw up some concerns with the club game and agreed release, so that would have to be changed.'

Within the corridors of power, the demise of the Nations League plan is likely to hasten the appetite for regime change. World Rugby chairman Sir Bill Beaumont had been determined to oversee a consensus agreement on this subject.

As all that signs are that he has been unable to do so, there is understood to be majority support for the current vice-chairman, Agustin Pichot, to take over the chairmanship from next May. His elevation is now regarded as a near certainty.