Steam Packet chief executive Mark Woodward has issued a response to the new competition his company faces for freight traffic between the Isle of Man and the United Kingdom.
In his blog on the company website, Mr Woodward confirms Mezeron's daily freight service poses a threat to the Packet's passenger services.
It comes a week after Mezeron launched a daily lift-on, lift-off container service between Douglas and Liverpool, which has already attracted supermarket chains Tesco and Shoprite.
Mr Woodward says the Steam Packet is not afraid of healthy competition, but if it is to benefit the end-users of his service, those involved must be competing for the same goal on a level playing field. This, he says, is not the case at present.
Mr Woodward points out revenues from the Steam Packet's freight service subsidise passenger fares, and says in similar markets elsewhere, such services cannot be provided without subsidy from the taxpayer.
He also draws a comparison between the two companies' fleets and crews. Mezeron's chartered ships are registered in Estonia and crewed by foreign nationals, while the Steam Packet's fleet is registered in the Isle of Man, and employs largely local crews on UK rates of pay.
Mr Woodward concludes the company will have to look carefeully at how an acceptable level of passenger services can be maintained in the light of tough competition for freight.