The first PMQs of 2012 was part-consensus, part-loggerheads.

Ed Miliband chose to tackle the issue of rail fares. It should have been a safe topic – after all, Ken Livingstone supporters froze their toes off handing out 'fare deal' leaflets when everyone went back to work last week.

'Last week' being the operative word – people have been back at work for a week and the topic risked seeming out-of-date. But the Labour lines were well rehearsed and Miliband needed a safe, confident topic after a shaky day yesterday.

Only, it may not have been that safe…

"The chancellor said in the autumn statement that train fares would only rise by one per cent inflation," Miliband said. It is now some 11 per cent, he added.

David Cameron had a short reply: "The power to do that was given by the last Labour government."

But Miliband seemed sure of his facts. "The PM is wrong. The last Labour government prevented them."

The only problem is, Cameron also seemed sure of his facts. "I know the Labour leader had a difficult start to the year. But I am afraid he is wrong."

"I am afraid the prime minister is just wrong about the facts," retorted Miliband. "The last Labour government saw that rail companies were taking advantage of passengers...

"He should get his facts right," he added (creeping back into his Mili-bot repetitive habits). "He is just wrong."

Thankfully someone must have given him a kick because he jolted to another line of argument. "The PM said at the weekend he would like to take action against crony capitalism… He has failed the first hurdle."

"If he wants to get onto the issue of executive pay, I think he is entirely right to raise the issue," replied Cameron.

Ahh, that's more like it. A bit of consensus.  And he only ruined it a little, by adding: "[Ed Miliband] is right to raise the issue of executive pay, and unlike the last government who did nothing for 13 years, this government will act."

But it seemed that a new tone had been set, because the next topic – Scotland – saw more agreement between the two party leaders.

Cameron is a pro-unionist and not in favour of Scottish independence on principle. Miliband knows that if the Scottish people were to vote 'yes' in a potential referendum, Labour would be unlikely to ever achieve a majority in Westminster again.

"We are stronger together and weaker apart," said Miliband. "We must make the [positive] case for the union."

"[This is an] area where me and the right honourable gentleman are 100% in agreement," nodded Cameron. "The first thing that is right to do is to make clear the legal position. I look forward to having the debate. I think that there are too many in the SNP who are happy to talk about the process... Sometimes, I think it is not a referendum they want but a neverendum."

Ed Miliband nodded and called for "immediate cross-party talks in Scotland" and "a serious, thoughtful, inclusive debate" over the independence question.

But the spirit of consensus couldn't last long.

The SNP's Westminster leader Angus Robertson stood, with a face so grave it should have been adorned with moss.  He accused Cameron of "emulating Margaret Thatcher" in trying to dictate to the Scottish people.

Oh well. They made a good stab at harmony for the first session of 2012.

Today's session came down to who is right and who is wrong. One topic will probably be resolved by the end of the day. The other will dominate politics for the next few years.

Interestingly, Miliband is potentially the biggest loser from both.

There is no such thing as a 'safe' topic for him at the moment.

UPDATE: The fact-checkers have pounced on the rail fares disagreement and it seems David Cameron was wrong. Today just got a little better for Ed.

UPDATE 2: Channel 4's FactCheck concludes that neither side "is being entirely straight" on fares. So there we have it... kind of.

Tags: PMQs, Rail fares, Scottish independence, Snp