Chief Secretary to the Treasury Danny Alexander will promise to keep pushing Spain to ease border restrictions as he visits Gibraltar.
Speaking at the Garrison Library on The Rock, the senior Liberal Democrat is to mark Europe Day by stressing the importance of free movement.
"On this special day, I reiterate the Government's firm commitment that we will respect your wishes on the question of sovereignty," Mr Alexander will say.
"The UK will never pass sovereignty over Gibraltar to another state against your wishes.
"And we will not enter into any process of sovereignty negotiations with which you are not content.
"I know that your relationship with Spain is a difficult one. And I am glad to have had the opportunity to come and hear first hand what impact that has.
"So, on this Europe Day, I ask everyone involved to think of the basic principles that underpin the European movement, particularly the free movement of people across internal borders.
"We are working hard to promote those principles and Gibraltar's right to enjoy their fruits. And we will continue to do so."
During his two-day visit Mr Alexander will witness the arrival of the Commonwealth Games Baton as well as inspecting border arrangements and the naval detachment that challenges unauthorised incursions into Gibraltar waters.
"Like so many parts of Europe, Gibraltar has witnessed some of the most damaging conflicts of the last century," he will say.
"Conflicts that ripped our continent apart inflicting misery on an almost unimaginable scale.
But since those early steps in the 1940s and 1950s that were to give birth to the European Union our generations have been sparred conflict of that scale.
"This year, we commemorate the 100th year anniversary of the First World War. Next month, HM (Her Majesty) the Queen will mark the D Day landings of 1944, the start of the liberation of Europe.
"It behoves us all to reflect that 70 years on, those countries sheltered within the framework of the EU are enjoying the longest period of peace and security in generations."