UPDATE 1-Local officials to approve Emsland reactor restart

*State wants plant's restart after repairs are complete

*Federal ministry previously demanded first right to approve

*State sets Aug. 1 deadline for any objections

(adds details, context)

FRANKFURT, July 31 (Reuters) - Nuclear supervisors in the northern German state of Lower Saxony said on Friday the Emsland nuclear reactor operated by RWE (RWEG.DE) was ready to restart.

They set a deadline of the afternoon of Aug. 1 for the federal environment ministry to object.

The 1,400 megawatt unit went offline last Friday but a faulty switch was replaced satisfactorily, the Lower Saxony ministry said in a statement.

The case had taken on a political dimension as the federal ministry, led by a different party, demanded to be given a final say over the restart.

"We intend to approve a restart (to test the function of the new switch) unless the federal ministry expresses substantiated concern by tomorrow afternoon," the statement said, without elaborating on when exactly the deadline will end.

RWE has said the plant is ready to operate again.

The problem comes when Germany's nuclear power plants are in the spotlight ahead of national elections on Sept. 27.

The Berlin-based federal ministry is headed by Sigmar Gabriel, a Social Democrat whose party shares power in a stormy coalition with Chancellor Angela Merkel's conservatives while Lower Saxony is ruled by the conservatives.

Gabriel has used a recent series of unrelated nuclear problems to highlight perceived safety risks which led to Germany's nuclear exit programme.

In contrast, the conservatives, forced to go along with the phase out deal agreed in 2001, will prolong the running times of those plants judged safe if they win a majority.

Gabriel issued two statements this week instructing Lower Saxony that his ministry must be satisfied first with security at the Emsland site before it allows the state to give the signal for the restart.

The Lower Saxony statement on Friday said there was no objective reason to deny a restart and a delay would be against the law.

(Reporting by Vera Eckert, Editing by Peter Blackburn)