Essex have indicated they could follow Nottinghamshire's example in future seasons by banning their players from taking part in the IPL during the English season as signs grow that the counties are considering a firmer line towards the tournament.

Paul Grayson, Essex's head coach, has admitted the issue has become a regular topic of discussion for the Essex committee as they consider withdrawing permission for their players to pursue IPL deals in 2014.

England's managing director, Hugh Morris, confirmed after their one-day tour of India that England's Test programme would remain sacrosanct and there would be no concessions in the new central contracts currently under negotiation and due to come into force in September.

England's centrally-contracted players who are in the running to play the first Test against New Zealand have to return by May 5 which entails missing nearly half the IPL which runs from April 3 to May 26.

The counties are responsible for issuing No Objection Certificates for players contracted directly by them - and the disruption they face is even greater with the Championship season beginning on April 10.

Nottinghamshire became the first county to stand firm and protect the integrity of the county season. Faced by losing Michael Lumb, Samit Patel and Alex Hales for the first part of the new season, a period which could conceivably end their Championship ambitions, Notts' director of cricket, Mick Newell, instructed his players not to put themselves in the IPL auction on February 3.

Essex's problems run just as deep. Ravi Bopara will be in the IPL auction and could become a third Essex player to potentially miss six County Championship matches and three CB40 fixtures of the new season. Ryan ten Doeschate already has a deal with Kolkata Knight Riders and Owais Shah is signed to Rajasthan Royals.

"It's something we keep discussing on a regular basis about what we're going to do," Grayson told the Essex Chronicle. "Eventually we might make a decision and say: 'Enough is enough: you either play for Essex or you play somewhere else'.

"Some counties are putting a stop to it and not letting their players go. Notts were the first ones that said if their lads go to the IPL then they don't play for Notts. It's up to them what they decide to do."

Middlesex will also suffer as Eoin Morgan has a contract with Kolkata but, as an England-contracted player, he is not bound by the wishes of his county. Last season Morgan played a full season of IPL when he was dropped from the England Test side and should be available to do so again with his selection for England's Tests against New Zealand in May unlikely after his exclusion from the tour party for New Zealand in March.

Essex do have control of their players because they are not centrally contracted and, although no decision about future policy has been reached, Grayson said the club are working with the ECB and the Professional Cricketers Association to avoid potential legal problems.

Their fear is that the situation could lead to players moving to counties willing to grant them a window to be available in the IPL. Only if all 18 counties followed the principle that the county season came first would English cricket avoid some high-profile transfers and even then they might not be able to hold the line against overseas players hoping for an IPL deal.

"If they're under contract, players can't do anything about it," Grayson said. "But if they're at the end of their contract they might go to another club that lets them go to the IPL, if that's what they want to do.

"It can be a bit of a problem but it gives one or two of the younger lads a chance to go out and show what they can do; the Mickleburghs, the Westleys and Foakes can come in and the others will have to wait their turn before they come back in to the side. Just because they go to the IPL there's no guarantee they'll walk back in to the side. You've got to be loyal to players, it works both ways."

Despite missing Shah and ten Doeschate for the first part of last season, Essex began well, winning one and drawing four of their opening five matches. When Shah returned, Essex lost to Derbyshire in their next match. But overall both Shah and ten Doeschate enjoyed good seasons. Shah made 589 runs in eight first-class matches at 49.08 and ten Doeschate 412 runs at 45.77 from his nine games as well as their impact in the limited-overs formats. Such players are not lightly lost.

Essex had batting cover at the start of the season with South African batsman Alviro Petersen playing seven matches, although he only managed 90 runs in 10 innings either side of making 145 against Glamorgan. This season, Essex have signed Rob Quiney, the Australian batsman, for the whole campaign.