TOKYO, June 23 (Reuters) - Japan's top court on Wednesday threw out a challenge by three couples who wanted to keep their own surnames after marriage, ruling that laws stipulating Japanese couples must choose one family name were constitutional, media reported.

The couples had argued that the provisions were discriminatory, pointing to growing public support for allowing married people to use different surnames.

Debate about allowing couples to use different surnames has become a hot topic among politicians after Yoshihide Suga replaced Shinzo Abe, who is thought to have more conservative views on the issue, as prime minister last year.

While some lawmakers in the ruling coalition support allowing couples to decide on what names they will use, a conservative wing of the ruling Liberal Democratic Party (LDP) has opposed it, saying such a step will damage family unity and go against tradition.