The cup final has traditionally been a valuable money-earner for the cash-strapped governing body but last year's disappointing attendance meant a reduction of around £800,000 in projected income.

Fearful of a repeat, the RFL asked both the Catalans and Toronto to lodge bonds, thought to be in the region of £500,000, in the event of either of them reaching Wembley in 2019 and, after refusing point blank to pay up, the Canadian club will not take part this year.

The Dragons have stopped short of threatening a boycott but have written to the governing body urging it to reconsider its request, with chairman Bernard Guasch claiming it would be irresponsible for his club to pay the bond.

In a statement, Guasch said: "The club has been officially advised in December that a £500,000 deposit will be asked by the RFL to play in the Challenge Cup in 2019.

"We, as a club, want to participate in this prestigious competition and defend our title but it would be irresponsible to accept this decision.

"Thus, we have asked the RFL to reconsider its demand and we are now waiting for a decision.

"The players would be very frustrated not to be able to defend their title and we hope that we'll have an answer as soon as possible. "

Because they are not full members of the RFL, both Toronto and Catalans Dragons have no automatic right to enter the Challenge Cup, but it would be a major embarrassment for the governing body if the holders are not in the draw for the sixth round in May.

In a statement, the RFL said: "We have been surprised and disappointed by the uncertainty over the Catalans Dragons participation in the 2019 Challenge Cup, which surfaced just before Christmas.

"We have been in discussions with the club since then, and will continue those discussions to search for a solution."

Coincidentally, the competition is set to break new ground when Serbian club Red Star Belgrade make their debut against Cumbrian amateurs Millom in the first round on January 27.

The RFL, which reported a loss of £2million in its last set of accounts for 2017, are still searching for a Challenge Cup sponsor after Ladbrokes failed to renew its backing.

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