The package has been keenly awaited as evidence that the former champions are back on track, but Monaco's special characteristics could make that hard to assess until Spain the weekend after.

A team spokesman confirmed on Thursday that the upgrades would be on the car around the tight and twisty streets of the Mediterranean principality.

Seven-times world champion Hamilton, who has not won a race since the end of 2021, had been particularly looking forward to Imola but Monaco is another old favourite.

"Definitely been counting down the days for it," the Briton said after the Miami Grand Prix when asked about the improvements. "I’m really hopeful that helps us take a step forward."

Once-dominant Mercedes decided they needed to go back to the drawing board with their 2023 car after they were only the fourth-fastest team in the Bahrain season opener. After five races they are third overall, 128 points behind Red Bull already.

Team boss Toto Wolff said in Bahrain that the car, whose slimmed-down sidepods are a marked contrast to the Red Bull that has won every race so far, was not going to be competitive without a change of concept.

Mercedes' trackside engineering director Andrew Shovlin recognised after Miami that continuing with the old package would not have allowed the team to fight for a world championship.

He said the aerodynamic changes marked "the first steps" in the right direction.

"We do hope that it is quicker, we hope that it's better in terms of qualifying and race pace," he added.

"The key thing though is that we are not just looking to bring a lap time update, we are looking to head off in a different development direction.

"One that we think gives us a better chance in the long term of being able to challenge for race wins and world championships."