Ofcom has hit back at Sky's implied accusation that the regulator was too slow in evaluating its proposed pay TV service on digital terrestrial television, Picnic.

On Friday, Sky announced an immediate suspension of preparations to launch the service despite indications as recently as July that it was searching for marketing firms to work on Picnic's rollout.

A spokesperson for the broadcaster said: "The blunt truth is that Ofcom has spent 18 months looking at our proposals and there is no end in sight. The Picnic team have done everything they can to prepare for launch and there’s nothing left to be achieved until Ofcom makes its mind up. While regulation works at its own pace, no business can go on like this indefinitely so we’ve had to take some pragmatic decisions."

Ofcom said that the proposal "raises complex issues, and is likely to have a significant effect on the future development of the pay TV market as a whole", and that "any decision to suspend the project is entirely a business matter for Sky".

In a statement it also said that it "rejects the implications of Sky's comments" and added: "Having announced Picnic in a press statement in February 2007, Sky took two months to submit the necessary application and a further two months to provide sufficient information to enable Ofcom to publish a consultation on the matter.

"When Ofcom consulted on both the Picnic proposal and the PayTV Market Investigation, several stakeholders, including Sky, responded late to these submissions. Sky submitted its response on the Pay TV Market Investigation over six weeks after the 26 February 2008 deadline.

"We have received a number of supplementary submissions from stakeholders after deadline dates which we are bound to consider. The most recent one from Sky arrived as late as 13 August 2008.

"Sky has raised a series of procedural points throughout this period, including a repeated concern that we are spending insufficient time considering its arguments."

It said it would aim "to conclude this work as efficiently as possible while carrying out our duties to promote competition in the interests of consumers and citizens".