The company plans to end the service from March 12th next as part of their cost cutting plans which have put them at loggerheads with unions.
Ahead of a public meeting in Clonmel this evening NBRU General Secretary Dermot O'Leary says they will not accept cuts to vital routes across the country.
He says Bus Eireann's decision to cut the Clonmel – Dublin service doesn't make sense.
The proposed changes are being resisted by both the NBRU and SIPTU with an indefinite all-out strike set to start on Monday.
The public meeting organised by the NBRU starts at 8 o’clock in the Clonmel Park Hotel tonight.
