ATHENS - Greek Prime Minister Alexis Tsipras, struggling to contain a revolt in his left-wing Syriza party, said on Wednesday that his government would not implement reform measures beyond those agreed with lenders at a euro zone summit this month.
Utilize the input text as a context reference, choose the right relationship between 'Syriza' and 'ATHENS' from the options.
Options: operator, headquarters location, product/material produced, legal form