Mr Sharkey, and his partner of more than 10 years, Ade Antigha, have instructed their solicitors to bring a case against the government on the grounds of discrimination.
Speaking from Spain, Mr Sharkey said he was not willing to wait for the possibility of legislation next year which may introduce same-sex civil partnerships.
"I'm with partner for over 10 years - how long do the government think it appropriate to wait for equality?" Mr Sharkey told ireland.com. "The law as it stands at this time is discriminatory on this fundamental aspect"
"We could have a ceremony here in Spain but it wouldn't be recognised at home in Ireland."
Mr Sharkey has received international recognition for his abstract paintings and sculptures and recently opened his own gallery in Co Mayo.
He and his partner Ade Antigha, a former police constabulary sergeant, live in Ireland but spend the winter months in Spain.
Following the introduction of civil unions for same-sex couples in the UK last week Minister for Justice Michael McDowell signalled that the Government will introduce legislation next year which would provide for civil partnerships.
He also committed to establishing a working group on civil partnerships.