European governments must stand shoulder-to-shoulder in the face of the eurozone financial crisis, UK Deputy Prime Minister Nick Clegg is to say.In a speech in Poland, he will say that if the crisis leads eurozone members to integrate further, it must not be at the expense of other states\' interests.\"Euro ins\" and \"euro outs\" must not develop opposing aims, he will say.Eurozone countries are continuing to struggle with the repercussions of Greece\'s debt crisis.European Commission President Jose Manuel Barroso has said the EU is facing \"its greatest challenge\".And he said that \"further changes to the Treaty of Lisbon\" may be required in order to push through measures to stabilise Europe\'s economy.\"Europe is clearly embarking on a period of change,\" Mr Clegg will tell the EU Eastern Partnership summit in Warsaw.\"The danger we face is of change leading to fragmentation - that we become divided, turning away from each other, both within the European Union and with our partners who are not, or not yet, members of it. That would be a disaster.\"He will continue: \"When it has counted most, Europeans have stood together - recognising that we are stronger shoulder-to-shoulder than we are apart.\"Now, we must do the same again.\"Mr Clegg will say that while the 17 eurozone members must decide the response to the current financial crisis, decisions that affect the whole of the EU must be made only by all 27 states.BBC political correspondent Vicki Young said the deputy PM would \"echo the chancellor\'s view that there needs to be more fiscal integration in the eurozone if current troubles are to be resolved - and that decisions must be made soon\".\"The world is impatient,\" Mr Clegg will say. \"The markets are desperate for signs of leadership and the eurozone does not have time on its side.\"But, we are also clear that any change to governance structures must not lead to a weaker and divisive Europe where the aims of \'euro ins\' are set against those of \'euro outs\'.\"Some Eurosceptic Conservative MPs consider possible EU treaty negotiations to be an opportunity to reclaim powers from Europe.However, their Lib Dem partners in the coalition government are playing down the likelihood of any such negotiations soon.Our correspondent said: \"The Liberal Democrats and the Conservatives don\'t pretend that there\'s much agreement between them on European policy.\"But they both see this as an opportunity to push ahead with the completion of the single market.\" From / BBC