'(1) A referendum is to be held, no later than 31 October 2011, on the voting system for parliamentary elections.

(2) The Secretary of State must-

(a) present to Parliament a Command Paper describing an alternative-vote system for consideration by voters in the referendum;

(b) by order made by statutory instrument specify the question to be asked in the referendum (and any statement that is to precede the question) and fix the date of the poll.

(3) The question specified under subsection (2)(b) must ask voters whether they would prefer the alternative-vote system described in the Command Paper to be used for parliamentary elections instead of the existing voting system (commonly referred to as "first past the post").

Any form of words to that effect may be used.

(4) In this section "alternative-vote system" means a system under which, for each constituency-

(a) one candidate is elected;

(b) voters must indicate their first-choice candidate and may also rank any or all of the other candidates in order of preference;

(c) votes are allocated to candidates in accordance with voters' first choices and, if one candidate has more votes than the other candidates put together, that candidate is elected;

(d) if not, the candidate with the fewest votes is eliminated and that candidate's votes are dealt with as follows-

(i) each vote cast by a voter who also ranked one or more of the remaining candidates is reallocated to that remaining candidate or (as the case may be) to the one that the voter ranked highest;

(ii) any votes not reallocated play no further part in the counting;

(e) if one candidate now has more votes than the other remaining candidates put together, that candidate is elected;

(f) if not, the process mentioned in paragraph (d) is repeated as many times as necessary until one candidate has more votes than the other remaining candidates put together, and so is elected.

(5) The reference in subsection (4)(d) to the candidate with the fewest votes, in a case where there are two or more candidates with fewer votes than the others but an equal number to each other, is a reference to the candidate eliminated in accordance with whatever provision is made for that case.

(6) The reference in subsection (4)(f) to the candidate with more votes than the other remaining candidates put together, in a case where there are only two remaining candidates and they have an equal number of votes, is a reference to the candidate elected in accordance with whatever provision is made for that case.

(7) A statutory instrument specifying the question to be asked in the referendum or fixing the date of the poll may not be made unless a draft of the instrument has been laid before and approved by a resolution of each House of Parliament.

(8) Subsection (1) and sections [Entitlement to vote] to [Restriction on legal challenge to referendum result] do not apply (and no further duty arises under subsection (2)(b)) if either House of Parliament, on a motion to approve a draft laid under subsection (7), decides not to approve it (unless the Secretary of State decides to lay the draft again under subsection (7), or to lay a revised draft under that subsection, and the re-laid or revised draft is approved by a resolution of each House).'.- (Mr. Straw.)

Brought up, and read the First time.