The CBI cautions against an energy bill price cap. 

Deputy director general Josh Hardie admitted low levels of people switching supplier to save money was a "challenge". 

There was a range of solutions to be tried, he said, adding:

Laura Kuenssberg
BBC political editor

Image source, Reuters

Many words have been written about capping energy prices since the then Labour leader Ed Miliband promised a freeze on prices in 2015.

It was dismissed as some kind of Marxism by the Tories back then - and again when Theresa May hinted at it in the autumn, and in this election campaign.

So for a Conservative leader to be pressing ahead with a hefty intervention in a market is quite something.

Read the rest of Laura's blog here.

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Plans to remove the market from the health service will be set out by Green Party co-leader Caroline Lucas later. 

At a policy launch in the Isle of Wight - a seat being targeted by the Greens - she will say: "A confident and caring country is one where we provide people with the healthcare they need, free at the point of use. 

"That's why my party is today promising an end to the pain of privatisation that has been inflicted on the NHS by Labour, the Lib Dems and the Conservatives - we will give the NHS the funding it needs to meet the challenges of the 21st Century."

She will describe the Conservatives' management of the NHS as "a cruel form of shock therapy".   

Conservative sources have told the BBC there was opposition to Mrs May's plan to impose a cap on energy prices when it was discussed at cabinet. 

Sources say among those expressing doubts was energy secretary Greg Clark.

It's understood Mr Clark favoured a "relative cap" that would allow energy companies more flexibility. 

The idea has been supported by a number of Conservative MPs. 

However it's understood Mrs May was determined to press ahead with her plan for a fixed price cap. 

We told you consumer expert Martin Lewis was relatively upbeat about the Tories' energy policy, but he's a lot less happy with the business secretary's admission that he's never switched supplier.

We've been up for ages (yawn), but in case you haven't, these are the main talking points so far today:

• The Conservatives promise to cap energy prices for people on standard variable tariffs.
• No, it's not 2015 - the business secretary insists Labour's planned energy price freeze back then was "a botched policy", but the Tories' is the right step to "protect the vulnerable".
• Labour is officially launching its election campaign this morning in Manchester.
• Jeremy Corbyn will argue that Brexit is a "settled" question - it will happen, no need to vote Tory "to strengthen Theresa's May's hand", he'll argue.
• Instead, Mr Corbyn will say, people should vote Labour to get the right kind of Brexit, one focused on jobs first and foremost.
• Tim Farron is campaigning in St Ives, Cornwall, a seat he's desperate to win back from the Tories.
• And the Greens are launching their health policy, promising to put an end to the "pain of privatisation" in the NHS. 

Image source, PA

One former chief exec from one of the big six energy suppliers welcomes a cap on the default energy tariffs -  because many people never switch supplier and they can feel confused by their energy bills. 

Paul Massara, formerly of nPower and now running North Star Solar, a renewable energy company, said bills just land in people's in-trays, and they struggle to work them out. 

A cap on energy tariffs is only part of the answer, says Greenpeace UK's Doug Parr.

He says governments will always reach for "populist policies, that grab headlines", but that shouldn't happen at the expense of "deeper solutions, which would really make people’s lives better".  

Today Programme
BBC Radio 4

On Monday, Theresa May threw herself wholeheartedly, once again, behind the target of cutting net migration to the tens of thousands.

Business Secretary Greg Clark was pressed on Today about where the cut in immigration would fall and when would it happen. 

"The key difference is we will have control over this policy in a way that we haven't in the past," he told Justin Webb.  

He said the government would "look at each of the sectors to say, 'what is the right policy for that?'".

The UK needs to develop skills domestically to meet industry's needs, he said, rather than looking abroad. 

But he would not be specific on when a Conservative government would be able to cut immigration.

People would know more "when the manifesto comes out", he added.

Image source, PA

Tim Farron is off to St Ives in Cornwall today, which is eighth on the Lib Dems' list of target seats. It would require a swing of 2.6% from the Conservatives for Mr Farron's party to win it back - the majority to overturn is 2,469.

How likely is it that to happen? Well, the Daily Mail's political editor, for one, is sceptical.

Sadiq Khan believes the prime minister has failed on key issues affecting the capital.

Consumer rights campaigner Martin Lewis says he's "not 100% persuaded" the Tories have the right plan for energy prices, but their idea of an absolute cap is much better than the alternative, a relative cap which would have narrowed competition.

"We have to hope (if they win) that it does the job intended," he concludes.

Today Programme
BBC Radio 4

Asked what had happened to free market conservatism, Greg Clark says it is still "being pursued with vigour" despite this intervention in the energy sector.

"It‘s always been a tenet…" he says, before being interrupted.

Part of the Conservative tradition has always been to open up state-controlled markets and put in place competition regimes, he insists. 

But the government has to make sure "dominant players cannot abuse their market power". 

BBC Radio 5 live

Image source, Getty Images

Former Lib Dem leader Nick Clegg, now his party's spokesman on Europe, isn't a fan of the energy price cap. And when it comes to the cost of living, he thinks Brexit is the big driver being a current squeeze.

"I think it's quite a complicated wheeze to say that you can get Ofgem to possibly put a cap on certain prices, and not on other prices and then the other people say well, in the long run that will actually discourage investment and competition," he tells 5 live.

"But what actually people feel right now and see right now, every time they fill their car with petrol, is that prices have gone up, and that is a direct result not only of Brexit, but also the way Brexit is being handled by this government."

Today Programme
BBC Radio 4

On the energy cap policy, Business Secretary Greg Clark points to a Competition and Markets Authority report which identified an annual figure of £14bn on average of overcharging by providers.  

A cap on the default tariffs people go on to, in a market where only 16% of customers switch providers to save money,  would help to protect vulnerable customers, he said, such as those without access to the internet.