Although the initial proposals that the Boundary Commission drew up proposed moving Bidston & St. James ward to Wallasey constituency (from 2015), the revised proposals place Bidston & St. James ward far more sensibly in Birkenhead constituency. The consultation on the revised proposals are running until 10th December 2012.
The effect of Bidston & St. James ward staying in Birkenhead under the revised proposals, is that Upton ward is moved in the revised proposals from Birkenhead to Wallasey (it’s currently in Wirral West, which is proposed to be renamed Wirral Deeside). These changes are of course subject to a vote in the House of Commons before 2015, which the Lib Dem Party has now stated they won’t support (although they agreed to it in the Coalition Agreement in 2010) because of stalled House of Lords reforms due (in part) to a rebellion by backbench Conservative Party MPs.