Trafford MBC is being monitored by the Information Commissioner's Office (ICO) following concerns about how quickly it is responding to freedom of information (FOI) requests.
The regulator said the council had failed to respond to a number of requests within the statutory time limit of 20 working days.
It warned that it could take enforcement action against the council if there were no improvements by the end of the month.
Gerrard Tracey, the ICO's principal policy adviser, said: ‘The law sets limits on how quickly public authorities must respond. Trafford has not been meeting that requirement and we'll now be reviewing its performance.'
A statement from the council read: ‘The council has been cooperating fully with the ICO since monitoring started at the beginning of May.
‘Measures have been put in place to help secure improvements in response times across the organisation.
‘Figures submitted in relation to requests received during May show that the percentage of responses returned within the 20-day limit was higher than the ICO's target for responses.
‘The council is looking to continue to build on this success.'