The Prime Minister said he had to dart home from Cornwall - a long-standing domestic holiday destination for the Camerons - in 2011 and 2013, as a lack of signal hampered his ability to keep updated on the fall of colonel Muammar Gaddafi, and the Syrian conflict, respectively.
Mr Cameron said: "This is a really big issue for people all over the country - the 'not-spots'. It's not good enough to say here's the mobile coverage for the whole country. You have got to recognise a lot of people are making important calls while they are on the move."
Ministers are already discussing plans to negotiate with mobile phone operators and asking them to help increase coverage by sharing phone masts, which would allow for the introduction of national roaming in the UK.
National roaming sees phones switching from one operator to another when service is not available through a particular provider, which is what happens when people travel abroad.
It would address the problem of partial "not-spots", areas where only some of the major networks are available.