A campaigner says he is prepared to go on hunger strike if calls to scrap a planned merger of Parliamentary constituencies from either side of the River Tamar fall on deaf ears.
Mike Chappell, branch secretary of the Celtic League Kernow group, will be one of many protesting against the creation of a cross-border constituency, dubbed "Devonwall", as part of plans to trim the number of MPs.
Members of the Keep Cornwall Whole group will stage their rally on the banks of the Tamar, in Saltash, on the Cornish side of the river, this weekend.
Group members, including its leader and Saltash town mayor Adam Killeya, say they are "rising up in protest at the obvious injustice of destroying, at one stroke of the Parliamentary pen, a historic border which dates back to the 19th century".
But Mr Chappell insists he will go much further in an effort to maximise publicity of their opposition to Devonwall. In an impassioned plea to anti-Devonwall campaigners, Mr Chappell said: "It is really time for us all in Kernow to say no to these politicians who really do not understand us, our land or the ordinary people I love in the land I love. Kernow is just too important for the London politicians.
"Wherever you are from, if you wish to be Cornish then so be it and I want Cornwall to remain a special place.
"This Government seems hell bent on destroying Cornwall and I urge you all to support this campaign. Kernow has her own heartbeat."
The campaigner said he is prepared to take desperate measures himself if the planned Parliamentary Voting System and Constituencies Bill fuses one constituency from electors across both counties.
He added: "If this (rally) fails, then those of you who know the enormous passion I feel in my heart for Kernow will understand and believe me when I say I shall deny food in a personal protest against the Westminster Government. I will not eat until they put right this proposed wrong."
A delegation from Cornwall recently met with Deputy Prime Minister Nick Clegg, urging him to consider Cornwall sacrosanct from merger plans.
But the Liberal Democrat leader last month rejected their calls, prompting further action from the Keep Cornwall Whole group.
Some members will spend this Friday and Saturday canvassing support from the public during a tour of the Duchy. Their rally will be held under the Tamar Bridge, from 2pm on Sunday.
For more information, visit www.keepcornwallwhole.org .