England's leading multi-format cricketers, including Ben Stokes, Jofra Archer and Jos Buttler, could be forced to miss the two-Test series against New Zealand in June, due to a clash with the knock-out phases of this year's IPL.

The trio, all of whom play for Rajasthan Royals, are the most prominent IPL players in England's Test set-up, although Chris Woakes (Delhi Capitals), Sam Curran (Chennai Super Kings) and Jonny Bairstow (Sunrisers Hyderabad) could also be affected if their respective franchises reach the final four of the competition.

Mark Wood is another potential absentee, if he gets picked up in Thursday's IPL player auction, as is Moeen Ali, who was released by Royal Challengers Bangalore at the end of last season, and whose absence from the final two Tests of the ongoing India tour is due, in part, to the prospect of two further months away from home if he is signed by another franchise.

Currently, the IPL has yet to announce either the dates for this year's tournament, or the venue, but it is likely to be held in India, starting around April 10 through to the first week of June.

That would have implications for England's build-up to their two-Test series against New Zealand, which is scheduled between June 2-14 and is not a part of the World Test Championship, having been added to the ECB's summer schedule in mitigation for their likely absence from the WTC final, which is scheduled for June 18-22.

On Tuesday, the IPL sent out an email to the franchises, seen by ESPNcricinfo, listing out the availability of players from top countries. Along with those from Australia, New Zealand, West Indies, Zimbabwe, Afghanistan and Ireland, England players were also listed to be fully available for the IPL, but with a caveat.

"In the event of ECB Selectors wishing to select a player for the 1st Test v New Zealand whose franchise has made it through to the knockout stages of the Tournament, but who is not featuring in the starting XI, the relevant franchise is requested to release such player early so that they can participate in the Test Match," the IPL email read.

The ECB has adopted a more flexible attitude to the IPL in recent years, with the tournament's high intensity and quality being credited as significant factors in England's recent rise in white-ball standards, culminating in their World Cup victory in 2019.

To date, no ECB centrally-contracted player has missed a Test match to take part in the IPL, despite frequent clashes with the English summer schedule in the early years of the tournament.

However, the ECB's rest-and-rotation policy for the ongoing tours of Sri Lanka and India has been designed to factor in the prospect of IPL involvement for their key players, particularly with the T20 World Cup due to be staged in India at the end of the year.

Stokes and Archer both missed England's two Tests in Sri Lanka in January, while Bairstow, Curran and Wood have been on leave in the UK during the Chennai leg of the India tour.

South African players' availability unclear

Some of South Africa's IPL players could also be impacted by the white-ball series against Pakistan at home in April. With the series scheduled between April 2-16, Kagiso Rabada and Anrich Nortje, Delhi Capitals' prominent pace partnership, are among those who are set to miss the opening few weeks of the tournament, along with Quinton de Kock (Mumbai Indians) and Faf du Plessis (Chennai Super Kings).

Cricket South Africa is yet to confirm the window that South African players will be available for in the IPL. But that would not have an impact on the likes of allrounder Chris Morris, who is likely to be one of the players to ignite a bidding war once again. Morris was one of the most expensive buys at the 2020 auction, after being bought by the Royal Challengers for INR 10 crore ($1.4 million USD approximately), but does not hold a central contract with the national team.

Lesser availability could impact Shakib, Mustafizur

There are no such issues concerning Australia and New Zealand players. Cricket Australia has confirmed that it will issue No-Objection Certificates to all its players from April 1 for the entire IPL, including for those that would otherwise be playing in the Sheffield Shield, while New Zealand Cricket has also made its players available for the entire tournament.

Players from South Africa, Bangladesh and Sri Lanka, however, will not be fully available. While Sri Lanka Cricket are yet to confirm dates, the Bangladesh Cricket Board has said that "any players selected will be unavailable from May 19 or will leave before if any other series is scheduled during IPL window."

That could impact the prospects of the Bangladesh duo, Shakib Al Hasan and Mustafizur Rahman, who are understood to have attracted interest from a few franchises in the lead-up to the auction.

Additional reporting by Andrew Miller