Cross bench peer Lord Cornwallis led the assault in last week's debate, accusing the government of imposing unnecessary change which would weaken local government power.
'I believe the review was originally instituted to deal with change in three specific places, since when it seems to have spread like an epidemic of measles across the country', he said.
The number of elected members in his home county of Kent could be reduced from 805 to 375 if unitary authorities were introduced, he said.
Lord Cornwallis highlighted the threat the government posed to the supposed independence of the Local Government Commission.
'Refusal by the government to accept the commission's recommendations for Derbyshire, Durham and Gloucestershire can only lead one to believe that they will only accept recommendations that coincide with their own pre-conceived wishes', he said.
Lord Bancroft, who was DoE permanent secretary from 1975 to 1977, said powerful local government was an essential counter balance to a wilful and over powerful central government.
'It is an open secret that at least twice the government has considered abandoning the review. Why not stop it now'? he asked.
Estimates of the costs of reorganisation varied wildly. While Lord Cornwallis claimed it would take 100 years to make a net saving in Kent, Labour peer Lord Jacques claimed the costs of making Portsmouth a unitary authority would be recouped in three and a half years.
By the time junior environment minister the Earl of Arran rose to reply to the debate 37 peers had said that they supported the survival of county councils compared with six who spoke in favour of unitary authorities.
He stressed the independence of the Local Government Commission and the importance the government attached to ensuring the benefits of reorganisation outweighed the costs of disruption.
He rejected the Association of County Councils' estimate that reorganisation would cost £1.1 billion.
The Earl of Arran said the estimates of savings expected by reorganising Cleveland and the Isle of Wight were encouraging.
'No change would indeed mean no transitional costs, but it would also mean no long term savings', he said.