MPs need to grow up!

While most of the UK basks in its very impressive standings in the 2012 London Olympics being currently 3rd on the medal table, a different kind of a game is being played out by the politicians on the streets  of London.
There are two piece of legislation that the two parties in the Coalition want and each has something to gain from one but there's a problem with how it can be delivered.
The Tories want to reduce the number of Members of Parliament probably a good thing given how much is done in Europe and the Devolved assemblies of of Wales, Scotland and Northern Ireland but by changing the constituencies in way that generally favours them.
The Liberal Democrats want to 'reform' the second chamber - the House of Lords - by having nearly all the Lords elected for 15 year period because they believe that gives them a ' democratic mandate' to act.
The problem with this is simple: Ever since the 1909 Peoples Budget and the constitutional clash between the Lords and The Commoners, the Commons had the final say and the Lords was a revising Chamber where members with experience and no party system to make them vote along those lines examined and suggested improvements to bills and could introduce new bils but they had to go the the Commons for approval.
It worked well in practise even if the Lords weren't elected and some who were entitled to attend didn't  but Tony Blair MP as Prime Minister half reformed it, removing some lords and putting political appointees in living it in limbo and creating a Supreme Court usurping some of the Lords former powers.
Now the one thing Commoners do not is a House of Lords that says "We represent the people" and start to challenge directly them so many Tories and a good many others who aren't Liberal Democrats have made it plain they won't vote for this.
In a pique of childish  behaviour, the Liberal Democrat Deputy Prime Minister has decided to block the changes in the number of MPs championed by the Prime Minister, Tory David Cameron.
To some as one who will admit to voting LD in the elections over here I find this stupid simple because of all the many pressing issues in modern Britain there's next to no interest by the public at large in changing how the House of Lords works. Actually outside of the Liberal Democrat supporters most would say they like it how it is.
If the Liberal Democrats had concerns about how the new seats proposed to reduce the number of MP's (and I can think of some affecting people near here ), then they should oppose them for those reasons alone, not childish tit for tac revenge.
Is there a grown up in the House of Commons?