Some of the providers of the new NHS non-emergency advice line have delivered an "unacceptable service", a Health Minister said today.
Earl Howe hit out at the quality of the some of the operators of the 111 line but claimed that across most of England people were getting a "good" or "fantastic" service.
His comments come after official figures today revealed a sharp rise in abandoned calls.
The number of people who hung up after waiting for more than 30 seconds increased from 6,976 in February to 29,100 in March, according to NHS England figures.
The average call length increased from 14.19 minutes to almost 18 minutes, while the number of calls to the line increased by more than half a million.
The Royal College of General Practitioners last week said patients had "lost confidence" in the new 111 number, which is yet to be fully up and running across the country.
The service was supposed to be rolled out on April 1, but officials were forced to relax the deadline after it emerged that many of the 44 individual local bodies that will run the line were not ready. Seven bodies are still not ready to start giving advice.
At question time in the House of Lords, Lord Howe said: "We recognise that the NHS 111 launches in March did not go as smoothly as planned and a number of providers have delivered an unacceptable service, especially at weekends.
"NHS England is working closely with clinical commissioning groups to stabilise providers who have failed to deliver an effective service and to ensure those areas yet to go live are in a safe and fit state to do so."
But shadow health minister Lord Hunt of Kings Heath demanded: "On what grounds was the decision made to go ahead with the national roll-out in the light of the results from the pilot which showed problems with the scheme and the fact that many people in the NHS advised ministers and NHS England that it should not have been rolled out because it was not ready to be rolled out?"
Lord Howe said Sheffield University had carried out research on the pilots which suggested high levels of satisfaction and that the service was sending people to the right places.
"On that basis it was considered safe to go ahead with the roll-out. Unfortunately, in particular areas of the country the resources deployed to meet the demand have not been accurately assessed," he said.
He added: "Across the vast bulk of England people are getting a good if not fantastic service. Unfortunately, in two particular areas of the country - the South East and South West - we are still seeing the problems arising - those are being gripped."