Japan’s parliament has failed to reach common ground on a revision of imperial family norms as a succession crisis looms over the future of the household.

Since last year, Lower House speaker Fukushiro Nukaga, together with his deputy and Upper House counterparts, have tried to muster a bipartisan consensus on the imperial rules — with no notable success.

For months, Liberal Democratic Party chief adviser Taro Aso and Constitutional Democratic Party of Japan leader Yoshihiko Noda — two former prime ministers — met behind the scenes in the hopes of fine-tuning an agreement.