Paul Hampton (Solidarity 194) seems (it is not totally clear) to oppose any constituency link when electing MPs on the grounds that it produces a result that is not exactly proportional to the votes cast for each party nationally.
That is wrong. Abolition of constituencies would mean that MPs would just be chosen from national party lists, putting more power into the hands of central party bureaucracies (and we already have some idea of what that means in the Labour Party!). It also removes any accountability of MPs to their electorate or to local party members. Finally, it robs constituents of anyone who directly represents them in parliament and who can be put under pressure by campaigning.
In short, it is fundamentally undemocratic. There are ways to combine a generally proportional result with a constituency system as the recent elections in Ireland show. Larger multi-member constituencies is one; combining a party list with a constituency system is another. Democracy, not pure proportionality, should be our aim in any reform of the electoral system.