The emergence of Alinta as the fourth serious contender for the pipeline has already drawn criticism from the other competitors and could see the whole process collapse due to a conflict of interest.

The current sales process is hanging on the pipeline’s major customers Alcoa, Alinta, Wesfarmers and Western Power agreeing to tariffs that would fund an urgently needed expansion to the line.

Now representatives of the three confirmed bidders, Australian Pipeline Trust, Envestra CKI and Prime Infrastructure claim that it will be impossible to come to commercial terms with Alinta if it remains as a competitor in the bidding process.

So far the sales process has continually frustrated the government and Eric Ripper’s attempts to secure a quick sale, and this latest development could see a further extension to the August 27 bidding deadline.

Alinta will reportedly make a $1.7 billion bid backed by Macquarie Bank and AMP with a plan to refinance the deal later by introducing the soon to list DUET. The end result would see Alinta holding a 10% stake, AMP/Macquarie 80% through DUET with the final 10% provided by another of the pipelines major customers.

However, the government has already ruled Western Power out of the deal and Wesfarmers said at this time it does not expect to participate.

A complaint to the Australian Competition and Consumer Commission (ACCC) is also on the cards due to a perceived conflict of interest in the Alinta bid, although is yet to comment on the process.