Viewpoints: MPs and peers on Ukraine
UK parliamentarians have been responding to the ongoing crisis in Ukraine. The BBC has collated a selection of their views.
Sir Peter Tapsell, Conservative MP for Louth and Horncastle
Brussels is partly to blame for this Ukrainian crisis.
If the already over-enlarged European Union is going to continue to try to extend its borders towards Mongolia, we will indeed finish up with a third world war.
Every Russian knows that the capture of Crimea and Sevastopol was the greatest achievement of Catherine the Great - that is why she is called "Great" - and Potemkin.
No Russian government of whatever political complexion could ever give up Crimea or Sevastopol, and we can be absolutely certain that the Russian people are passionately in support of President Putin over this issue.
Sir Menzies Campbell, ex-Lib Dem leader
It is difficult to take the protestations of President Putin seriously in the light of the incident recently reported about Russian soldiers firing warning shots over the heads of Ukrainian soldiers seeking to go about their lawful business and then threatening to shoot them in the legs if they did not desist.
That merely emphasises the fragility of the present circumstances, particularly the risk that either provocation or miscalculation could lead to a conflagration.
Peter Hain, former Labour Foreign Office minister
Clearly, there is tremendous provocation from President Putin.
However, in the end, this situation will be resolved diplomatically - or it will not be resolved, with terrible costs to the whole world.
Former Conservative defence secretary Liam Fox
We're dealing with a bullying and thuggish regime.
We've got to make it very clear that we regard the whole concept of a near abroad and their sphere of special influence as being anachronistic and destabilising and we must constantly make sure that sovereign nations are able to exercise their self-determination without hindrance or interference.
We're going to have a lot of very nervous allies in Nato, particularly the Baltic states and some of the former eastern European states that border what Russia calls its sphere abroad.
They'll be looking for better reassurances from Nato that we absolutely guarantee their security in the future. We may want to do more military exercises; we may find very obvious ways of showing that we have their security at heart and that the alliance actually means something.
It's also now imperative that Nato raises its game on its political role.
During the Cold War we combined both military strength with a very clear political role that we were not going to allow communism to roll over into Western Europe. We need to start to develop some of the same messages for Moscow again.
Labour MP for Rhondda Chris Bryant
Poland and the Baltic states are increasingly nervous of Russia's expansionist tendency.
There are still Russian troops in Georgia.
Is it not therefore all the more incumbent on us - the European Union as a whole - to stand up, united and calm but extremely robust, lest Crimea become a 21st-century Abyssinia or Sudetenland?
Sir Edward Leigh, Conservative MP for Gainsborough
Surely we must ensure that we cannot be accused of double standards.
We were rightly prepared to violate the territorial integrity of Serbia to protect the right to self-determination of the Kosovans.
Presumably, we should look equally kindly on the right to self-determination of the ethnic Russians in Crimea and Donetsk.
Therefore, can we please resist the wilder talk of economic sanctions, which can only damage the fragile recovery of Europe, and instead engage in diplomatic dialogue with Russia and Ukraine?
Lord Davies of Stamford, former Labour defence minister
There's a very widespread feeling in the world that Vladimir Putin's ultimate ambition is to restore the frontiers of the Soviet empire and the Tsarist empire.
If he succeeds in de facto occupying, or even one might say de facto annexing, the Crimea, that will surely be a great encouragement to him to proceed along that agenda a little bit further. Indeed, he'll probably become a great hero to nationalist sentiment in Russia.
Against that background, isn't it extremely important, not merely that we have the right sanctions to apply - if it isn't possible to achieve some diplomatic solution as we all hope over the next few days and weeks - but also that we look again at the long-term signals that we're sending to Russia?
In particular, we should review two things. One is the dependence of the EU on Russian natural gas, and surely as an urgent strategic priority we should try to reduce that. And secondly, the deplorable signal we've been sending, along with many other EU countries, in reducing our defence expenditure.
Terrible tragedies have happened in history because the wrong signals were sent to a potentially aggressive party.
Crossbench peer and ex-diplomat Lord Hannay of Chiswick
It is quite clear that Russia has not fulfilled its obligations, either as a member of the Council of Europe, or the Organisation for Security and Cooperation in Europe.
The future position of Russia in those organisations [should] be... under consideration.
Lord King of Bridgwater, ex-Conservative cabinet minister
Out of a clear blue sky, suddenly we find ourselves in an extremely dangerous situation, in which there is a lot of fear around. And a lot of fear on every side at this present time - it is important to remember that.
We need the greatest restraint on all sides, and we need the earliest possible meeting together of Russia and the Ukraine with the contact group.
I was defence secretary and paid an official visit to the Soviet Union at the time it was breaking up. One thing that came across very clearly was that while they regretted the passing of some other members of the Soviet Union, the one they really minded about was the Ukraine.
It has a particular sensitivity to them, and... the Crimea in particular.
These things need to be discussed around the table, and not with bullets and guns in the streets.