The statement assumes significance, as it comes after BJP leader Nitin Gadkari met Raj Thackeray here today.
RPI is a member of the Shiv Sena-BJP led alliance of five opposition parties in the state, called 'Maha-yuti' (mega-alliance).
The other two members are Raju Shetti's Swabhimani Shetkari Sanghatana and Mahadeo Jankar's RSP.
"We would welcome Raj Thackeray if he joins the Maha-yuti," Athawale said here this evening.