Local MP Alan Mak has pledged his support for Gibraltar retaining its British status.
He made his views clear during a meeting with Jonathan Scott, the Gibraltar Government's UK representative and head of Gibraltar House in London.
Gibraltar, a British Overseas Territory on the southern tip of the Iberian peninsula next to Spain, is home to a British military garrison and naval base.
It has been ruled by Britain since 1713, although it is self-governing in all areas except defence and foreign policy.
The UK has been negotiating with the EU and Spain to finalise a post-Brexit Treaty that allows the free movement of goods and people across the border with Spain.
But Spain continues to claim sovereignty over Gibraltar and this long-running territorial dispute shows no signs of ending.
Meanwhile the Labour Government's intention to surrender sovereignty of the Chagos Islands, another British Overseas Territory, to Mauritius has set a precedent that will not have escaped Spain's notice.
Mr Mak said: "Gibraltar has been under British rule for more than 300 years and Gibraltarians are British citizens. They don't want to be Spanish and I fully support Gibraltar continuing to be a British Overseas Territory."
