LGIM, part of insurer Legal & General, said it had "long-standing concerns" about Metro Bank for its lack of independent directors, poor gender diversity, pay structure and failure by the company to manage conflicts of interest.
After voting against the re-election of the chairman and approval of the pay report last year, this time round LGIM said it would vote against the Chair, members of the Audit Committee and directors with whom it has independence concerns.
LGIM said it was taking the "rare step" of pre-announcing its intentions ahead of the meeting on Tuesday in order to share its concerns with other investors.
"We hope that in sharing our voting intentions early, and that following the results of the AGM, this will help encourage Metro Bank to strengthen their governance structures," said LGIM's Sacha Sadan, director of corporate governance.
LGIM, which manages more than 1 trillion pounds in assets, is the 11th biggest investor in Metro Bank, data from Refinitiv showed.
(Reporting by Simon Jessop, Editing by Iain Withers)