Must clause 4(1) of the Framework Agreement on fixed-term work concluded by ETUC, UNICE and CEEP which forms part of the Community legal order by virtue of Council Directive 1999/70 1 be interpreted as meaning that termination of a temporary ‘contrato de interinidad’ to cover a vacancy when the term for which the contract was concluded by the employer and the worker expires constitutes objective grounds justifying the Spanish legislature’s not providing in such a case for any compensation whatsoever for the termination of the contract, whereas compensation of 20 days’ pay for every year of service is provided for in the case of a comparable permanent worker dismissed on objective grounds?