Public concern about changes to Cornwall's political map will be voiced at an inquiry starting on Tuesday.
The county is actually entitled to a sixth MP
Due to a rise in population, the county is getting a sixth MP, which will require a shake-up of constituencies to accommodate the extra seat.
The changes, which will be implemented by the Boundary Commission, were first recommended in a report in June 2003, but will not come into force until after the next General Election.
However, the proposed move has caused more than 90 objections to be filed by constituents across the county.
Cornwall currently has five constituencies: North Cornwall, South East Cornwall, St Ives, Falmouth-Camborne, and Truro and St Austell
But the commission says the county's current voter population of about 385,000 entitles it to a sixth MP.
Under the Boundary Commission's proposals, the seats of North Cornwall and South East Cornwall would match the local district councils.
Three of the seats would also see constituencies changed to include St Austell and Newquay, Truro and Falmouth, and Camborne and Redruth, which would include the Lizard but not Helston.
The Falmouth-Camborne MP, Labour's Candy Atherton, said she thought it was a good idea.
She said: "As the population in Cornwall is rising, there are more and more demands for the time of MPs.
"Another voice in Westminster is another voice speaking up for Cornwall - and I think that's a good thing."
However, St Ives' MP, Liberal Democrat Andrew George, said there should be some streamlining, meaning fewer MPs and not more.
He said: "The 659 MPs currently in the House of Commons is far too many.
"What we should be doing in Parliament is asking how to reduce the number of MPs so that we can actually talk about enlarging constituencies instead of cutting them down."
Chris Ault, team leader for the Boundary Commission in Cornwall and the Isles of Scilly, said: "The commission has to review constituencies roughly every 10 years.
"They've looked at the electorate in Cornwall and the Isles of Scilly and decided that they do warrant an extra seat.
"There are a lot of things to be discussed and all concerns will be addressed.
"If anyone wants to speak about any concerns, then they should address the inquiry."
The inquiry is being held at County Hall in Truro and is expected to last at least two days.