As pensions has raced up the political agenda with the arrival of auto-enrolment in the workplace, Labour has turned to one of its coming men to take the fight to the Coalition.

Gregg McClymont, a Cumbernauld high school boy who became an Oxford history don in 2007 and the area's MP in 2010, has been shadow pensions minister for two and a half years.

That's a longer stint than any of the 13 frontbenchers who played pass the parcel with the job of pensions minister in the last Labour government, and it is getting him taken seriously.

He is also adding weight in Labour's referendum battle with the SNP, helping Gordon Brown launch a Keep our British Pensions campaign in Fife last month, in a rare public foray for the former PM.

"It was a packed hall," he says. "We were making the case that the big idea that Labour has is that by sharing resources we ensure that those in need have their needs met - and pensions is the classic example of that."

Mr McClymont says the pension promises in the SNP's White Paper "depend on the maintenance of a pan-UK regulatory system", yet Scotland might have to create its own regulator, compensation scheme, and protection fund.

He notes that the Scottish accountants' institute, as well as the National Association of Pension Funds, have warned that cross-border final salary schemes might need to be fully funded within a far shorter period than the typical 10-year recovery plan of many schemes - assuming Scotland is EU-regulated.

He says: "Once you create a border, the terms and conditions for contributions and benefits on which Scots have paid into UK-owned company pension schemes are no longer valid."

The shadow minister appears happy enough with his Coalition adversary Steve Webb's higher flat rate pension for all from April 2016, because he says it is building on Labour's edifice of pension credit.

Criticised for its waste and its erosion of incentives to save, the Brown means-testing crusade has, for his disciple, "lifted 1.3 million pensioners out of poverty" and reduced pensioner poverty in Scotland by two-thirds.

He says pension credit "redistributed £75 billion from those who can afford it to those in need", and both the Coalition and the SNP are effectively using it as a benchmark for the new flat-rate pension.

But it is the emerging unease over the costs and governance of workplace pension schemes, now that huge waves of smaller companies are reaching their 'staging dates' for auto-enrolment, that is pressing political buttons. It is enabling Mr McClymont to argue that LibDem Mr Webb, after a long tenure of the pensions brief and a series of well-regarded reforms, is running out of steam just when it matters. "Big companies in auto-enrolment have got pensions expertise and muscle, they are going to get good deals from pension providers, that is a very different scenario when you move to smaller employers."

Unfazed by Mr Webb's promise this week of full transparency on pension charges, Mr McClymont wants a three-pronged attack on the market, targeting charges, scheme governance, and small pension pots that are abandoned and forgotten.

Whereas Mr Webb proposed a charge cap and then retreated, apparently with no plans for one till next year if at all, his shadow wants an early charge cap of 0.75% on the total expenses of a fund. He points to the 0.5% levied by major player Legal & General that has said it should be the industry norm, while he admits that a cap "is not a solution in itself".

Mr McClymont's key reform would be to follow Australian practice to achieve "scaling up", giving the pensions regulator the power to force small schemes to merge if they are not delivering value for money, and giving schemes a fiduciary duty to assess that issue.

That would enable pension companies - and four of them already run 70% of workplace schemes - to oversee all schemes with independent governance committees, which would have a fiduciary responsibility to the saver not the pension company or fund manager, a principle advocated by the Office of Fair Trading.

The MP also says Mr Webb's proposal to require 'stranded pots' worth less than £10,000 to be transferred to the holder's new pension scheme, when he moves employment, does not go far enough.

Mr McClymont says: "We can make a virtue out of the stranded pots issue under a Labour government."

Providers could bid to take over the pots and run them in "kitemarked" schemes with low charges and proper governance, he proposes.

The 37-year-old bachelor, who lists his hobbies as playing football, supporting Airdrie and Barcelona, and following cricket, golf, tennis and the Stone Roses, says he knew nothing about pensions when he got the call from Ed Miliband to leave the whips' office and take the brief in 2011. "One of the advantages of coming in fresh is I didn't have any preconceived notions - I started off by doing a lot of reading."

Mr Webb, meanwhile, is highly knowledgeable and "cares about pensions", but is "perhaps not doing enough to upset the applecart", his opposite number claims. State pension reform had been achieved, but "the things he suggested had to happen alongside that, haven't happened".

For the Labour man, it is the rush to personal pensions 25 years ago that has resulted in the proliferation of 'group' schemes at work which are based on individual contracts - with powerless savers. "If you proceed on the basis of every individual for himself, I don't think we will get there," Mr McClymont says.

He says the same applies to annuities - which the Financial Conduct Authority has now admitted are being used by the industry to make excess profits at savers' expense.

Labour's amendment to the current Pensions Bill would require all schemes to direct retiring members to an independent annuity brokerage approved by the regulator.

The FCA's slow pace has been widely criticised, and Mr McClymont says: "If government knows there is a problem, government has to act."

On why Labour failed to act on many such issues in its 13 years in power, the new boy MP admits: "That is a legitimate point." But he insists: "The 2008 crisis illuminated problems in financial services which had not had light cast on them."