GWYNEDD has the most holiday homes in England and Wales, with Anglesey not far behind.
2011 census results revealed more than 12,000 second homes in Gwynedd and over 5,000 across the Menai Strait.
Arfon AM Alun Ffred Jones said the “frightening” figures emphasised the urgent need to tackle Gwynedd’s housing problems.
He said: “Every week in my constituency surgeries I come across people who are unable to find somewhere decent to live, whilst too many houses are standing empty in our villages after local families have often moved away because of a lack of affordable housing , either to rent or buy.”
Mr Jones said house prices were “far too high” in relation to wages, and added holiday homes had played their part in pushing local people out of the housing market.
He said: “To redress the balance we need a mechanism to identify second homes as a category so that their numbers can be controlled. If necessary the Council should be able to impose higher rates on second homes.”
The figures amount to around seven per cent of Anglesey homes and nearly 10 per cent of properties in Gwynedd.
Campaigners Cymdeithas yr Iaith Gymraeg and Cymuned have raised concerns over the effect of holiday homes on the Welsh Language.
Anglesey councillor Richard Dew,who represents Rhosneigr ward, said more affordable housing was needed in the area.
He said: “There are new homes being built that have been focused on holiday homes and that’s a concern for me and for local people.
“They cannot afford new homes and they have to move away. In the end, the village suffers because of a lack of local people.
“Tourism is very important to the area, but we need to look after the local people.”