BOSTON — A key legislative committee is set to unveil its version of the state’s $40 billion budget for the fiscal year that begins in July.

The spending plan expected to be announced Wednesday by the House Ways and Means Committee comes amid signs of improvement in the state’s overall financial picture. Nine months into the current fiscal year, revenue officials said tax collections were running nearly $900 million above benchmarks.

Two potential November ballot questions are casting uncertainty over budget projections: One proposal would increase revenues through a four percent surtax on the state’s highest earners, while the other would lower revenues by reducing the state sales tax.

The House spending plan will be the first since Boston Democrat Jeffrey Sanchez was named to head the powerful Ways and Means panel.