Sixteen chief executives from Australia's top phone and internet providers have banded together to demand the Government come clean on how much it plans to contribute towards the cost of its data retention scheme.

The telco CEOs today penned a letter to Attorney-General George Brandis and Communications Minister Malcolm Turnbull to demand transparency on the funding allocation ahead of the planned debate of the proposed legislation in the House of Representatives tomorrow.
The Coalition Government has thus far neglected to provide a firm figure for its contribution to the regime, and has backed down in its language from promising a "substantial" chunk of funding to a "reasonable" one.
Consultancy PricewaterhouseCoopers has reported the implementation of the scheme alone would cost between $188.8 million and $319.1 million.
Telcos and internet service providers have said such costs would need to be passed on to consumers as part of their monthly bill.
The CEOs - from the likes of Telstra, Optus, Vodafone, M2, iiNet, Macquarie Telecom and others - today urged Brandis and Turnbull to detail the dollar figure the Government will provide to the telco industry to facilitate the potential introduction of the legislation.
"Our request to you is, we believe, relatively simple and reasonable," the telco bosses wrote.
"It is that the Government provide to industry, the parliament and the wider community a degree of certainty as to the size of the Government's planned contribution (and the planned methodology for apportioning those funds between Carrier/Carriage Service Providers of differing types and market shares) in advance of the bill being debated and potentially passed into law."
The chiefs said they recognised there was a significant cost range in the PwC estimates, that the Government was factoring in costs based on some recommendations from the parliamentary committee investigating the bill, and that there were budgetary implications arising from the funding allocation.
But clarity on the Government's contribution was necessary to allow carriers and ISPs to work out how much they will need to spend on the scheme and pass on to customers.
Detail on the methodology that the Government will use to apportion its contribution to various members of the industry will also influence the extent to which smaller ISPs and carriers will be affected by the scheme, the group of executives wrote.
"In light of these factors, we believe it would be a reasonable action on the part of the Government to - at the very least - provide a firm indication of the Government contribution, express as a percentage of the final determined cost," the CEOs wrote.
"We look forward to the Government's early response on this issue, particularly given the bill is scheduled for debate this week."
The data retention bill is expected to pass the Coalition-majority House of Representatives, but is likely to face more difficulty in the Senate thanks to opposition from the Greens and a number of crossbenchers.
The Labor party has signalled its support for the bill now that its recommendations for changes to the legislation have been adopted.