By Alastair Macdonald BRUSSELS (Reuters) - A proposal to give the EU's executive the power to send forces unbidden into member states to defend the common European frontier will face resistance from some countries when it is published this week. The European Commission wants to be able to deploy personnel from a new European Border and Coastguard Agency without, as currently required, the consent of the state concerned, EU officials told Reuters in early December, reflecting frustration with Greek reluctance to seek help with migrants. European Union officials call it a largely theoretical "nuclear option" and stress that any infringement of national sovereignty would be balanced by the power of a majority of member states to block Commission intervention - similar to checks agreed during the euro debt crisis.