The government said there is currently less demand for evening appointments for PCR (polymerase chain reaction) walk-in tests which are sent off to a laboratory.
Late opening community sites across England - including in Shropshire and Telford and Wrekin - currently close at 8pm but from November 1 will be closing at 6pm.
The move comes at a time when transmission rates are rising resulting in those taking positive lateral flow test results at home or are being pinged by the Covid NHS app, need to visit walk-in facilities for PCR confirmation checks.
Telford MP Lucy Allan has pledged to look into the matter and said the main issue is for all those who are eligible to get the Covid-19 vaccine, the booster and flu jabs.
She said residents experiencing any difficulties in getting doses should contact their local MP who will make representations on their behalf.
A Telford & Wrekin Council spokesman said: "Testing sites will be closing early across the UK not just Telford and Wrekin.
"Testing sites are not well used after 6pm and this is why the change has happened.
"People can order home PCR testing kits if testing site opening times are not suitable."
The Department for Health and Social Care stated: "We have built flexibility and scale into our services so that we can adjust quickly to changing circumstances during the pandemic and we will continue to do this.
"NHS Test and Trace works in partnership with other service management providers to operate symptomatic test sites across the UK.
"All service management providers have been informed of the decision to change future operating hours at regional and local test sites in England to 8am until 6pm from November 1 as demand for tests reduces significantly after this time.
"Twice weekly testing refers to asymptomatic testing – twice-weekly lateral flow tests.
"This has no relevance to the change in operating hours for confirmatory PCR testing sites."
Serco which also operates several sites across the region including the Black Country said it was among "four companies managing test centres" on behalf of the department in England and Northern Ireland.
The company further stated that it was in the government's hands over the issue operated approximately just "20 per cent of the total" number of centres.
Sites affected include:
Shrewsbury - London Road, Column.
Oswestry - Beatrice Street.
Newtown - Shortbridge Street.
Telford - Ironbridge Park & Ride, Jiggers Bank; Wrekin Road, Wellington; The Place, Oakengates; Wood Bowling Club, School Road, Donnington; Legges Way, Madeley.