The NRL will throw the ‘world’s biggest birthday party’ for Jai Arrow as the league starts making good on its promise to back the Souths star to the hilt as he battles motor neurone disease.

Arrow, 30, revealed his diagnosis on May 20 and is currently receiving treatment at a health centre in Spain.

Now the NRL will ask fans to make donations instead of bringing presents to mark Arrow’s birthday on July 12, when his Rabbitohs play Newcastle.

The league has also green-lit a proposal to create ‘Jai July’, a month-long fundraising effort to support the former Queensland State of Origin star.

‘We will throw the biggest birthday party in the world,’ NRL supremo Peter V’landys said on Wednesday.

‘It will be a huge occasion with the whole game involved.

The NRL is organising a month of fundraising to support Jai Arrow (pictured), including holding the 'world's biggest birthday party' for him on July 12

The NRL is organising a month of fundraising to support Jai Arrow (pictured), including holding the ‘world’s biggest birthday party’ for him on July 12