Unease is growing in the internet industry that Microsoft's decision to close its MSN chat rooms is only the start of a campaign against other sectors and services on the internet.

Malcom Hutty, regulation officer for the London Internet Exchange, the hub for the internet's backbone in the UK, believes Microsoft's decision was the direct result of a "sophisticated political campaign".

Hutty argued that non-governmental organisations such as the National Children's Homes charity, with, he said, a limited understanding of the internet, would now be encouraged to ramp up pressure on remaining internet service providers (ISPs) to close their chat rooms, and would then turn their attention to other services.

He warned that to hold ISPs responsible for everything bad that happened on the internet would lead to companies being forced to close their services down.

"Where exactly is this leading? If perfect safety is the only standard we can tolerate, will the next target be an 'open, free, unmoderated' website? Or will the next demands be to close down email? Because that has its own dangers too," he said.

Experts believe that closing all chat rooms will simply drive users to other less-regulated sites.

Yahoo, which would not comment on MSN's decision, said that, as part of the Home Office's taskforce on child protection, it is "constantly reviewing" policy.

ISP Freeserve was "somewhat bemused" by Microsoft's decision. It felt MSN should have consulted more widely with providers, as many of them are working with the Home Office on the problems. It also accused Microsoft of being unwilling to invest in better safety features.

"Chat is an intrinsic part of the internet and it's not going to go away. We know about the problems of chat rooms but the answer is not shutting them down, it's about constantly looking at ways to make them safer," Freeserve said in a statement.

"While giving the impression of being respectable and responsible what they are doing is nothing short of reckless."

But Microsoft denied the charge, saying it is pushing its free, more secure instant messaging service. It also dismissed accusations that the move was money motivated.

"Finances had nothing to do with it. We have no plans for paid-for chat rooms in the UK. There are paid-for subscriptions in the US because we have a different business model there as we offer ISP services," said Matthew Whittingham, MSN's UK head of customer satisfaction.

Mark Mulligan, senior broadband analyst at Jupiter, commented: "Chat rooms are not a revenue-making service and are a drain on providers' revenues. But in Europe consumers are not yet ready to pay for these types of services."