Prime Minister Shinzo Abe's ruling coalition is set to win a solid majority in an upper house election later this week, keeping alive his dream to revise Japan's pacifist constitution, a survey showed on Monday.

Abe's Liberal Democratic party (LDP) and its coalition partner Komeito together are on track to win as many as 83 seats, well over the 63 seats needed for a majority of the 124 seats to be contested on Sunday, the poll by the Nikkei business daily conducted late last week showed.

Similar polls taken by other media outlets, including the Kyodo news agency, showed support for the LDP had increased to 31.0% of all respondents, up 2 percentage points from a similar poll last month. Support for Komeito was unchanged at 5.6%.

Such a showing could enable the ruling bloc and other smaller parties including the Japan Innovation Party, which support constitutional revisions, to maintain their "super majority", or two-thirds of the vote. Such a majority is needed to start the process of revising Japan's post-World War Two pacifist constitution.

Changing the constitution to enshrine the role of Japan's military, known as the Self-Defense Forces, has been a long-held goal for Abe, who has been prime minister and leader of the LDP since 2012.

Constitutional revisions require approval by two-thirds of both chambers of parliament and a majority in a public referendum.

Upper house elections are held every three years, with members' terms running for six years. The LDP won a landslide victory in 2013 but fared less well in 2016. (Reporting by Naomi Tajitsu Editing by Paul Tait)