Australia's players face a ban from this summer's Ashes series should they take part in any kind of "disapproved cricket" in the event of an extended pay dispute beyond the July 1 expiry of the current MOU between Cricket Australia and the Australian Cricketers' Association.

The warning to all players, whether they are in or out of contract after the MOU expiry, was issued by CA's team performance manager Pat Howard on Wednesday night via state associations and also sent to the ACA, though it was not directly relayed to the Australia women's team currently taking part in the World Cup in England. Potential for the staging of exhibition games has been discussed among the players in recent weeks, while the prospect of many taking part in overseas Twenty20 tournaments is also in the wind.

However Howard wrote in his email, seen by ESPNcricinfo, to remind players that ICC regulations dictate bans of at least six months on any players taking part in matches not staged under the auspices of national boards. Equally, CA would also deliberate on whether players would be given No Objection Certificates to play in overseas T20 competitions on a case-by-case basis.

"Players (including uncontracted players) cannot play in ICC approved cricket (e.g. domestic T20 competitions operated by overseas cricket boards) without approval from Cricket Australia," Howard wrote. "Players who participate in disapproved cricket (e.g. exhibition matches) are not permitted to participate in ICC approved cricket for a minimum of six months thereafter."

With the Ashes due to start in November and conclude in the first week of January, such a ban would rule anyone playing exhibition matches out of contention for the England series. These words provided a stark reminder of the cliff edge Australian cricket has reached, two days out from the expiry of the MOU with neither party showing any sign of changing position on the fundamental of their disagreement - CA's determination to end the fixed-revenue-percentage model, and the ACA's resolve to retain it.

Players falling out of contract on July 1, including all CA-contracted players such as the national captain Steven Smith and his deputy David Warner, were likewise warned against entering into commercial arrangements with sponsors in conflict with CA's commercial partners. They were also told that any delay in reaching an MOU agreement beyond July 14 - the date when current contract offers expire without the signing of a new deal - would not be addressed with any back pay.

"If your contract expires on 30 June, you will not be an employee of CA, a State Association or a W/BBL Team from 1 July," Howard wrote. "This means that you are not required to play, train, perform player appearances or media commitments, and you will not be paid a retainer until such time as a MOU is agreed and a player contract is agreed with you in writing.

"If a MOU is agreed on or by 14 July, your playing contract would only commence from the date the MOU is agreed. CA does not intend that retainers would be back paid to cover any elapsed period between your current contract expiring and the execution of a new contract when a new MOU is agreed."

play 3:46 What exactly is the Cricket Australia-ACA pay dispute? What is Cricket Australia proposing under the new pay system and what are the players' demands? Have a look in this explainer

The commercial warning was particularly pointed given the ACA's foundation of the Cricketers Brand, a new commercial wing of the association devised to take control of the players' intellectual property after July 1. "All players will be provided with a list of protected sponsors for 2017/18," Howard wrote. "Any player entering into unapproved endorsements during any uncontracted period puts at risk future endorsement arrangements with CA, State and W/BBL partners and puts you at risk of not being able to enter into a contract for the upcoming season with CA, the State or W/BBL Team."

Howard's communique featured other interim advice for all players, stating that none would be locked out of training facilities beyond July 1 whether contracted or not, though players not on multi-year deals "are not required to train". Also included were interim arrangements for medical expenses and accident and health insurance, including a promise to work operationally with the ACA on insurance rollovers beyond the expiry of the MOU.

The ACA has called on CA's chief executive James Sutherland to enter negotiations directly with his counterpart Alistair Nicholson, with the association planning on a meeting of its executive - the president Greg Dyer, Aaron Finch, Moises Henriques, Neil Maxwell, Lisa Sthalekar, Janet Torney and Shane Watson - on Sunday if no agreement has been reached.