It's been called the mother of all deals in the Indian telecom space. After today's development, it seems like mother Kokilaben may need to step in to make it happen. That's because her two sons Anil and Mukesh are at war again.

In a stunning twist in the tale of Reliance Communications-MTN merger story, Reliance Industries wrote to the MTN board saying that it has right of first refusal over a sale of controlling stake in Reliance Communications. In effect, this would make any sale of controlling stake in the Anil Ambani-owned Reliance Communications to anyone but Mukesh Ambani-owned Reliance Industries illegal.

Any majority stake sale should be informed to all settlement parties, RIL said. When contacted, RIL spokesperson declined to comment on the issue.

Reliance Communications said that RIL's right of first refusal claim is legally and factually untenable, baseless, and misconceived. "RIL's claim is based on a unilateral agreement signed by its officials in 2006, which was pronounced unfair and unjust by the Bombay High Court in October 2006. Its action is anti-consumer, anti-investor, and anti-globalisation. It has made a malafide attempt to disrupt Reliance Communications, MTN talks."

Reliance Industries has asked Reliance Communications to show the agreements between the two companies to prove that there is no right of first refusal. Reliance Industries is also saying that despite being sent a legal letter, neither Reliance Communcations nor MTN have replied, stating their legal position.

In response Reliance Communications has said that it has responded to Reliance Industries' letter which claimed that it held a right of first refusal. It has also called RIL's claims legally and factually untenable. Reliance Comm also says that it had rejected on the same day an agreement that was signed on Jan 12, 2006, as Reliance Communications was still under Mukesh Ambani's control. On Thursday, RIL communicated its right of first refusal to MTN.

Is MTN rattled? Will it continue with the 45-day exclusive negotiations:

MTN said it had received RIL's letter, but it was unsure of the veracity of the information. It added that it is aware of the Ambani dispute, but it will continue talks with R Comm. But sources in Reliance Industries say that in case the deal between R Comm and MTN is successful it will seek damages. So, another chapter opens up in the saga of the Ambani brothers disputes.

Even as the battle between the two Ambani's rages on, wire agencies report that a team of MTN officials have quietly landed in India to continue talks with Reliance Communication on the deal.