Top Welsh Premiership sides to face Scottish Super 6 clubs
Last season's top six Welsh Premiership clubs will play in a cross-border competition against Scottish Super 6 sides at the end of the 2019-20 season.
Merthyr, Cardiff, Pontypridd, Ebbw Vale, Llandovery and Aberavon will face Ayr, Boroughmuir, Heriot's, Melrose, Stirling County and Watsonians.
There will be promotion and relegation for the Welsh Premiership for the first time since 2016 with one up, one down.
Indigo Group will take over as title sponsors of the competition.
Principality has stood down as sponsors of the semi-professional league after 14 years, although will continue to sponsor the national stadium in Cardiff which is celebrating its 20-year anniversary.
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Specsavers will be the title sponsors of the WRU National Leagues and Cup.
The first cross-border competition will take place in April and May 2020.
There will be automatic relegation for one Welsh Premiership club, providing the winner of the Championship meets the A Licence criteria.
This replaces the play-off system that last season saw Championship winners Pontypool fail to regain a place in the top division after losing 27-16 to Premiership strugglers Llanelli.
Pontypool are among the Championship clubs with a licence to go up.
Bedwas, Cross Keys, Bargoed and Neath were relegated as the Premiership was cut from 16 to 12 teams at the end of last season.
Triple Welsh Premiership champions Merthyr will launch the defence of their title at RGC on the weekend of Saturday, 7 September, before travelling to Pontypridd in round one of the Welsh Cup.
Merthyr head coach Dale McIntosh said, "First and foremost, we are all excited about the new season. Having 12 teams in the league will make it a stronger competition, I think we all produced some great rugby for the TV games last season and look forward to that level of profile again this season.
"We will look forward to the challenge of a new, cross-border competition and give the Scottish teams the respect they deserve."
It is anticipated the competition will continue to be televised on BBC Wales and S4C next season.