MP's must not abstain from voting.
MP's are elected,and paid to represent their constituents therefore should not be allowed to abstain from voting on issues. I feel that to do so undermines the rights of those people who voted for them to be represented. If for reasons of conscience they feel that they cannot vote on a particular issue, they should be required to represent the majority view of their constituents as recorded by the MP's local office. This will reflect the wishes of those constituents who have taken the trouble to get involved. Such a rule may encourage greater political involvement by voters in the UK and reduce the current levels of apathy.