Pro-Serb opposition parties have long opposed the government's aim of seeking NATO membership. This stance is in part linked with continued ill-feeling over the NATO bombing of Serbia and Montenegro during the 1999 Kosovo conflict, when the two countries were still united in the Federal Republic of Yugoslavia. The issue is complicated for the government by the fact that it would not be able to attain the required two-thirds parliamentary majority in favour of joining NATO without the support of at least part of the opposition. The alternative would be to hold a referendum on the issue. However, the outcome of a referendum would be uncertain, with opinion polls showing a larger proportion of respondents opposing NATO membership than supporting it.

In a speech in mid-November the foreign minister, Mr Rocen, alluded to the possibility that PzP support for NATO entry could help to secure a two-thirds parliamentary majority. Mr Medojevic quickly responded that, although the PzP supports NATO membership, the government could not count on his party to provide the votes needed in parliament, stating that the matter should be decided in a referendum. He claimed that the DPS's support for NATO membership was insincere, and that the ruling party did not in practice want democratic control over the security services or to fight against organised crime.

As in a number of previous instances, this issue revealed the awkward position of the pro-independence PzP when it finds itself supporting a policy advocated by the government. While not wanting to give any succour to the ruling parties, it does not wish to break ranks with its partners in the pro-Serb opposition parties either. The PzP's support for the new constitution, adopted in October 2007, resulted in enormous rancour between it and the pro-Serb parties, which had bitterly opposed its adoption, and the ensuing distrust has never been entirely dispelled. Mr Medojevic would be loath to risk damaging relations with his opposition allies. That said, he is also wary of identifying too closely with parties representing the Serb minority, realising that to defeat the DPS he will need to win broad support, including attracting some DPS voters.

Divisions within the SNP have also emerged, among other issues over policy on NATO membership. The SNP has always been less stridently pro-Serb than NOVA, stressing that it is a Montenegrin party, although it opposed the break with Serbia at the time of Montenegro's independence referendum in 2006. As part of a desire to reshape the SNP's policy and public image, a number of its officials have started to advocate a change of approach, with the SNP presenting itself as a civic, Montenegrin party. However, at a meeting of the SNP's main committee in November the pro-Serb majority rejected a proposal calling for the display of the Montenegrin flag and the singing of the Montenegrin national anthem at the party's forthcoming congress.

In another attempt at a break with the past, the reformers inside the SNP have started to support NATO accession, which continues to be opposed by prominent party figures-including a former SNP leader, Predrag Bulatovic-who insist that a referendum should be held before Montenegro joins the alliance. Opponents of NATO entry say that participation in its Partnership for Peace (PfP) programme, seen by many other countries as an anteroom for eventual full NATO membership, is a sufficient basis for relations with the alliance.