SYDNEY (Reuters) - Support for Australia's Prime Minister Malcolm Turnbull is at a two-year high, an opinion poll showed on Monday, a boost for the center-right government ahead of a series of by-elections at the end of July.

The last Newspoll before the July 28 by-elections showed Turnbull's personal popularity at 48 percent, its highest since the 2016 general election, and above opposition Labor leader Bill Shorten at 29 percent.

Turnbull's popularity could help the government's chances in the five by-elections, one analyst said, despite Labor's 51-49 lead over the governing center-right Liberal-National coalition.

"There will be some voters that vote on preferred leader. Turnbull will be pleased," said Peter Chen, a political scientist at Sydney University.

Local polling ahead of the by-elections suggested the vote was likely to be close in two contests.

The by-elections were triggered after opposition politicians were forced to resign over their status as dual citizens.

A victory would ease the pressure on Turnbull, who holds a one-seat majority in parliament and has been forced by coalition partners to adopt policies he previously opposed.

In November 2017, Turnbull announced a wide-ranging inquiry into the scandal-hit finance sector, reversing his government's opposition to such a probe.

(Reporting by Colin Packham; Editing by Darren Schuettler)