By Mike McKimm BBC Northern Ireland environment correspondent

Mobile phone companies in Northern Ireland have been dreading the changes which have now finally arrived.

Consultations with the environment committee at the Northern Ireland Assembly had made it quite clear that the new proposed planning legislation for phone masts would be tough.

But few expected it to be this tough.

All new masts must have full planning permission.

Changes to existing masts must have full planning permission.

The relative attractiveness of Northern Ireland as a location for inward investment could be reduced and future job creation jeopardised

Federation of the Electronics Industry

Prior Approval for masts under 15 metres has been abolished.

Previously, these masts needed little official paperwork and could be erected after just a 42 day waiting period.

Neighbourhood notification must take place - ensuring local people know what is being planned.

In addition, a new planning policy statement comes into force immediately.

This document sets out substantial criteria any new masts must meet, including health checks and visual and environmental consequences.

The industry has lost no time in stating its concern.

A spokesman for the Federation of the Electronics Industry (FEI) which represents Northern Ireland's mobile phone operators, said the legislation was disappointing.

Telecoms infrastructure

"By imposing full planning procedures on all telecommunications development the relative attractiveness of Northern Ireland as a location for inward investment could be reduced and future job creation jeopardised," he said.

In another surprise, the phone user watchdog, the Northern Ireland Advisory Committee on Telecommunications (NIACT), said the tough laws were not good.

The chairman, Courtenay Thompson, warned Northern Ireland would fall behind in terms of telecommunications technology if the legislation was implemented.

"It is essential that we continue building a telecoms infrastructure in Northern Ireland that will be in line with the rest of Europe," he said.

"The Republic of Ireland has completely relaxed the law in the area of mobile masts, so we, in the north, may end up with a much poorer network than the rest of Europe."

Dermot Nesbitt: Legislation put before assembly

Just when the Environment Minister, Dermot Nesbitt, may have thought that, given the endless complaints about phone masts, this would be a big winner with everyone, the problems begin.

Grumbles from the industry were expected but the criticism by the phone watchdog will have come as a surprise.

NIACT's problem is they have a specific remit - to ensure that people using phones get a good service.

They estimate that close to one million people in Northern Ireland use a mobile and half of them are unhappy with the service and reception they get.

That means a need for more masts.

There are already about 1,200 masts in the province with another estimated 500 to be erected to meet the needs of existing systems and roll out the new third generation - 3G.

Shared masts

Protracted planning for new masts would have driven the phone companies to use existing masts. But the new legislation means they also need full permission to alter these.

In launching the planning policy, the DOE, who control such matters, specifically identify mast-sharing as a way forward.

However, some industry people are already pointing out that this will also attract full planning permission, so companies would be less inclined to go down this road.

Why make all the effort to share a mast when you could just apply for a new one? Both need full planning permission.

The assembly will have to vote in due course on the legislation.

If they vote it out, the planning criteria remains, but full planning permission for new masts and any changes would be abandoned.

It will be a brave assembly member who tells their constituents that they voted to allow more masts to be built.

But if the industry falters as some warn it might, then the same assembly member will have to explain why they voted for a poorer service.