Harman joins Cameron at Isil security briefing amid Syria strikes speculation
Labour's interim leader Harriet Harman joined David Cameron and other senior ministers for a briefing from security chiefs on the threat from the Islamist terror group Isil.
Mr Cameron has previously said he would like to secure cross-party consensus for any extension of military airstrikes against Isil to targets in Syria, and the decision to invite Ms Harman to the scheduled meeting of the National Security Council is likely to be seen as a further step to prepare the ground for a possible parliamentary vote in the autumn.
The interim Opposition leader was accompanied by shadow defence secretary Vernon Coaker and foreign affairs spokesman Dan Jarvis.
Mr Cameron's official spokeswoman said the Prime Minister made clear at the start of the meeting in Downing Street that it was not an event at which decisions would be made, but an opportunity for politicians to get an up-to-date picture from experts on the scale of the Isil threat in the wake of the murders in the Tunisian holiday resort of Sousse.
"This was an opportunity for those around the table to hear from experts their assessment of the situation, the nature of the threat, our response and to put questions to the expert community," said the spokeswoman.
"They looked at both the domestic threat and that overseas to the UK from Isil, particularly from Iraq, Syria and Libya."
At the meeting to give expert advice were National Security Adviser Sir Kim Darroch, the chair of the Joint Intelligence Committee Jon Day, MI5 director general Andrew Parker, MI6 chief Alex Younger, the director of the GCHQ eavesdropping centre Robert Hannigan, Chief of Defence Staff General Sir Nick Houghton and Foreign Office permanent secretary Sir Simon Fraser.
Asked whether the meeting was part of a softening up process ahead of a vote on extending military action to Syria, the PM's spokeswoman said: "The Prime Minister has been clear throughout - and he reiterates this at the meeting - that he thinks the biggest threat to our national security comes from Islamist extremism and particularly from Isil.
"This was an opportunity to have a discussion about that and about our response. The PM's view on this issue and whether or not there is a case for taking action in Syria, he has talked about before and that hasn't changed. He has been clear he wants to approach this with consensus. He thinks it is important that people understand the nature of the threat.
"We are still of the view that more thought and more deliberation is needed before we decide whether to return to Parliament on the issue. But this is part of making sure that people understand the nature of the threat."