All of Smart's 40,000 telephone customers were cut off at the beginning of October when Eircom ceased supplying services because of a 4m debt owed to it by Smart. They were later reconnected after the communications regulator Comreg intervened.

For the past month, these customers have been provided with a limited telephone service, not including international calls. The deadline to find another operator expired last Saturday and Eircom has since cut off the remaining Smart subscribers.

A spokesman for Comreg said the regulator had contacted many of the customers affected by phone in recent weeks and had also sent them a letter advising them of the situation and of how to go about transferring to a new operator.

Over 6,000 customers did switch in the week leading up to the deadline but, according to the latest figures from Comreg, around 6,500 ex-Smart users have now been cut off.

Those affected will be able to use their phones to make emergency calls using 999 but will not be able to make or receive any other local or international calls until they sign up with a new provider.

Operators including Eircom, which leased its phone lines to Smart, have been busy snapping up the stranded customers of the troubled telco.

Eircom has been the most successful, signing up over 60% of the 33,000-plus Smart users who have switched providers so far.

It appears many of those who were burned by their experience with Smart have opted to go back to the former Telecom Eireann, shunning the advances of some of the newer entrants such as Magnet, Perlico and Carphone Warehouse, which all ran advertising campaigns targeting the former Smart customers in the wake of the dispute with Eircom.

Smart has accumulated liabilities of 40m in the course of an ambitious but ill-fated attempt to establish itself as the leading competitor to Eircom in Ireland. The company was acquired two weeks ago for the nominal sum of 1 by its largest shareholder, millionaire businessman Brendan Murtagh.