The Welsh Government has been accused of "hampering" democratic scrutiny after taking eight months to respond to emails from an opposition politician.
Plaid Cymru's Rhun ap Iorwerth wrote to ministers in June about Covid testing, but did not receive a response until this month.
It follows concerns last year from the Conservatives about the speed of government replies.
The Welsh Government said its first priority was to save lives.
Mr ap Iorwerth, Member of the Senedd for Ynys Mon, wrote two emails to ministers on the 18 June, raising constituents' concerns about the Covid-19 testing process.
In his reply, dated 10 February, Health Minister Vaughan Gething wrote: "I apologise for not replying sooner.
"The Welsh Government has received an unprecedented amount of correspondence regarding the pandemic and we are working to respond to each enquiry as quickly as possible."
Mr ap Iorwerth also wrote to the government on 1 September to raise concerns about the use of facemasks in supermarkets and got a response on 9 February.
"When a day is said to be a long time in politics, imagine how much can change in eight months, and yet this is the length of time it can take to get a response to a written question from Labour Welsh Government," Mr ap Iorwerth said.
"Our Senedd website boasts 'effective scrutiny of government is at the heart of any democratic process' but I would argue that this is seriously hampered by the painfully slow response times to written questions."
It is not the first time ministers have been criticised for providing slow responses during the pandemic.
The Welsh Conservatives accused the Welsh Government of an "unhealth aversion to scrutiny" in April 2020.
The group's leader at the time, Paul Davies, wrote to First Minister Mark Drakeford saying: "I appreciate that we are in the midst of a national emergency with Covid-19 and that the Welsh Government's resources should be, quite rightly, focused on battling the virus and ensuring the safety of the people of Wales.
"However, as members of Wales' legislative body we have a duty to scrutinise your government".
The Welsh Government's website states that ministers "aim to reply within 17 working days, however due to the increased volume of correspondence being received currently, we may take longer".
The Welsh Government said it had see a 350% rise in correspondence since the start of the pandemic and responded as quickly as possible.
A spokesman added: "However, the staff who manage our response to the pandemic are also responsible for responding to correspondence and other government business.
"Our first priority has been on putting in place a unprecedented series of measures to save lives and livelihoods.
"To allow Members of the Senedd to scrutinise the work of the Welsh Government, and to help the public understand the measures we've put in place, we have taken a deliberate approach to ensure a comprehensive collection of information and guidance about our approach to tackling coronavirus is up to date and available on the Welsh Government website."