0905 : Far-left members of Greece's ruling Syriza party have revealed plans to form a splinter party, Popular Unity, following the resignation of Prime Minister Alexis Tsipras and calling of snap elections overnight.
What is the relationship between 'Syriza' and 'Alexis Tsipras' in the context of the input sentence.
Options: chief executive officer, chairperson, employer, product/material produced