The MSP says numbers of motorhomes using island ferry routes has “shot up nearly tenfold” over the last decade .
But there is a lack of suitable sites and waste disposal units for them, he said.
In addition the extra space that they require on the ferries has contributed to capacity problems on ferries over the summer, he maintained.
Alasdair Allan has raised the idea of a “motorhome levy” with transport minister Humza Yousaf.
Mr Allan said: “It has been a fantastic thing for our local economies in the Western Isles that we have had record numbers of tourists visiting here and enjoying our island hospitality.
However, this success has brought its own set of problems and it is readily apparent that our infrastructure has not been able to keep up with demand.”
He added: “While there has been substantial and welcomed investment by the Scottish Government in new and larger ferries we need to recognise the continued pressure on local people trying to travel in the busy summer months.
“Motorhomes play an important part in our tourist economy and this should not be about making motorhome visitors feel unwelcome. They are welcome.
“This is about recognising the pressures created on infrastructure by such a rapid growth in tourism and providing communities with a new source of funding that they can direct as they see fit.”
Impose levy on motorhomes coming to the Hebrides says MSP
20 Sept 2017
Western Isles MSP Alasdair Allan says a motorhome tax should be introduced to help improve island infrastructure.