By Martha Kearney
Presenter, BBC Radio 4's The World at One
Parliamentary recess, or half-term to the normal world, can be a difficult time.
Mr Cameron is facing mutterings of 'mishandling' grammar schools
In the past I have found it a useful opportunity to take a holiday, so have ended up in the wrong place during a political storm.
Last September I was away in Turkey during the September "coup", when a number of Labour politicians put pressure on Tony Blair to set a date for his retirement.
I had to rely on texts to keep me up to date on twists and turns of that dramatic week.
Even worse was the time I was in Cuba during Peter Mandelson's second resignation.
I hadn't seen or read any news, so only realised what had happened when I saw a passenger's Telegraph on the plane home. I practically ripped it out off his hands.
Apart from missing the drama of the story, you never quite catch up on the nuance: how briefing on day one has changed by day three.
One of Alastair Campbell's political rules is that politicians are only in deep trouble if a story stays in the headlines for 11 days.
David Cameron must be worried because the grammar school story refuses to go away, even though he has insisted it must and called the discussion "a sterile debate".
On Monday one frontbencher with grammar schools in his Greater Manchester constituency, Graham Brady, briefed the Times with figures he said showed that selection was best for performance across an area.
He got a roasting from the whips.
By Tuesday afternoon Mr Brady had decided to resign, perhaps going before he was pushed in the next reshuffle.
The concern about grammar schools is widespread.
Our producers have been tracking Conservative MPs in far-flung holiday destinations and many have told us off the record about their worries - not simply about education policy but also about shadow chancellor George Osborne's speech this week.
In it he claimed that Cameron's Conservatives would follow Tony Blair's path on public service reform, not Gordon Brown.
This "heir-to-Blair" strategy is designed to portray the next Labour leader as a roadblock to reform.
A former Tory spin-doctor, Nick Wood, told BBC Radio 4's The World At One that the strategy was "too clever by half" and would infuriate the Tory grassroots.
On Thursday came a story in the Evening Standard about an article by a senior shadow Cabinet member Dominic Grieve, arguing that new grammar schools should be built where needed.
This apparent act of rebellion stirred the pot further. Mr Willetts told us there was no contradiction with his policy: local areas could decide to build new schools if necessary.
The impression left, however, is that a concession has been made and there are more mutterings about "mishandling" and "poor presentation".
David Cameron's primary goal in the first years of his leadership has been to convince the country that the Conservatives have changed - that they are no longer the nasty party.
One way to do that is the classic New Labour tactic of triangulation - attack your own party and provoke a row to prove that you occupy the centre ground.
This can be risky.
In power Tony Blair has always had an uneasy relationship with the Labour Party.
Battles with public sector staff like teachers and health service workers have meant that plans for reform often met with resistance.
There are signs that David Cameron may have difficulties with his grassroots.
One of his inner circle told me of their fears that the modernisers were only a tiny group within the Conservative Party - that the vast majority are simply going with the flow because they think Cameron will make the party electable but any wobble in the polls and the doubters will be quick to pounce.
This should have been a golden period for the Conservatives, given the current Labour power vacuum.
Tony Blair is off on his "Nellie Melba" farewell tour as John Major described it.
Gordon Brown himself is off on "a listening tour" of the country to prove that he's not a Stalinist control freak, so we're not hearing any new policies from him just yet.
The contest for the Labour deputy leadership seems to be based on who can appeal most to the left of the party.
The Conservatives could have seized the initiative but instead are getting headlines about disunity.
That kind of negative coverage will have to be addressed by their new director of communications Andy Coulson.
That could be tricky, as the new policy commissions begin to report, giving rise to many more debates along the lines of the grammar school row.
David Cameron must be looking for ways to assert his authority. Look out for a reshuffle soon.