Boris Johnson will address Tory MPs on Tuesday ahead of Commons votes on his plan for easing lockdown.
The Prime Minister will speak to the Conservative backbench 1922 Committee to defend the Government’s approach, which will see some restrictions remain in place in England until at least June 21.
On Thursday MPs will be asked to approve the regulations for the road map and extend some of the emergency powers in the Coronavirus Act for a further six months.
Critics, including former chief whip Mark Harper, have warned the continuation of restrictions is “draconian” because the success of the vaccination programme means they are not needed.
But Ms Stratton said Mr Johnson believed “this is a cautious but – if we do it right – irreversible road map” which would take time because of the need to assess the impact of each measure.
The Government’s plan would see shops and pub beer gardens open on April 12 at the earliest, with indoor hospitality allowed from May 17 if all goes to plan and the final stages of lockdown being lifted on June 21.
“So, taking the time to do it in the way that we are doing, with the five-week review points (between stages), means that we are sure at every point that the loosening is the right thing to be doing,” Ms Stratton said.
“That’s why it is taking its time, because we want to make sure we are doing the right thing.”
In a move which could win over Tory MPs uneasy about the continuation of the Coronavirus Act, the Government indicated it will remove or suspend 12 measures which are no longer required.
They include provisions on emergency volunteers which could have come into force if the delivery of health services was at risk and the end of an extension to time limits for retaining fingerprints and DNA profiles.
