More than 700 street lights in Northamptonshire will have to be replaced after council bosses revealed contractors had fitted a set of dim temporary bulbs without informing the public.
Since 2011 Balfour Beatty has been gradually replacing all of the county's street lamps with more energy-efficient lanterns as part of a 25-year Private Finance Initiative (PFI).
But recently some areas had become concerned the new replacements were extremely dim.
In Burton Latimer, 10 street lights were so dull it led to a number of complaints.
At the county council's full meeting on Thursday it was revealed that in fact 715 street lights across Northamptonshire have been fitted with a temporary bulb without prior warning.
A spokesman for Northamptonshire County Council said: “A supply problem with some of the lanterns for the Northamptonshire street light replacement programme meant that some street lights had to be fitted with a temporary lantern.
“Once the correct lanterns can be supplied, they can quickly be swapped over. This is a temporary solution at no additional cost to the council."
It is understood the supply problem was caused by strike action at the factory in which the bulbs are made.
But there is frustration that councillors were not warned of the lower watt bulbs being installed.
Councillor Michael Brown (UKIP, Kingsthorpe North) said: "This is an issue of openness.
"The council keeps hiding things all the time. All they had to do was send out an email, I think people would have liked to have known."
Burton Latimer town councillor Christopher Groome said he only discovered the wrong bulbs had been fitted after he asked the a county council highways officer to join him on a walkabout of the town.
The temporary bulbs have been in place there for five months, but were replaced immediately after Thursday's full council meeting.
There are currently 715 lights countywide which are fitted with a temporary lantern.
In relation to the 10 bulbs in Burton Latimer, a council spokesman said: "These lanterns were replaced as a priority, with the work taking place on Thursday last week.
“The council continues to monitor the situation, is fully aware of the affected streets and will ensure that contractual obligations with respect to the council’s lighting standards are met.”