Cable company NTL has defended its decision to charge its more than half a million customers a surcharge for late payments and for refusing to sign direct debit mandates.

The company was criticised yesterday by the chairwoman of the National Consumer Agency, Ann Fitzgerald, for deciding to charge customers an extra €2 per bill if they do not pay by direct debit.

Customers who do not pay their bills on time will be charged €7.68.

Forcing customers to sign up to direct debit payments was a "major issue", particularly for older people, Ms Fitzgerald said.

"Forcing consumers to go the direct debit route has very serious implications for poor and vulnerable people who do not have a bank account."

While companies were entitled to recoup money for late payments, €7.68 was "very high", she said. Ms Fitzgerald was speaking on RTÉ radio yesterday.

She also criticised the quality of service provided by NTL, particularly their customer service line which was "impossible" to access, she said.

A spokeswoman for UPC Broadband, the parent company of NTL and cable providers Chorus, said Chorus was already operating the late payment fee and it was being introduced to NTL to standardise both operations.

The charge for not using direct debit was not being applied until next April so that customers had adequate notice of the change, she said. The company would be "mindful of individual cases" where direct debits would cause hardship, she added.