London Briefing: Some prefer National Rock, others Northern Wreck or the People's Bank, but the most apt name now for the nationalised Northern Rock business is simply the Safest Bank in Britain.

The controversial government decision to take the Newcastle-based mortgage lender under full state control puts Northern Rock in a unique position. Not only is it being propped up by taxpayers' cash, it is also being run by a team appointed by the treasury.

Heading that team is the respected company doctor Ron Sandler, best known in the City of London for hauling Lloyd's of London back from the brink of collapse in the 1990s.

Chancellor Alistair Darling - or "dead man walking" as he has been dubbed by the media - continues to insist that state backing for what was once Britain's fifth-largest home loans provider will not distort the market.

Quite how that fits with Sandler's assertion that the bank will "compete vigorously" with its rivals remains to be seen and there is still the possibility that the European authorities will query the new set-up.

Since it was forced to go to the Bank of England for emergency funding five months ago, Northern Rock has been quietly getting on with the business of parting savers from their cash.

It regularly tops the table of "best buy" accounts with a series of deals that leave its rivals in the shade, such as an online account aimed at the over-50s which pays out 6.49 per cent, or its three-year savings bond paying out 6 per cent.

It's not so keen on getting customers' mortgage business - not surprisingly, perhaps, as that's where its problems started - and its rates there are noticeably less competitive than its rivals.

But it is the gilt-edged guarantee of savers' money that really gives Northern Rock the edge on its rivals and where the other banks could rightly argue that it has an unfair advantage.

While other high-street banks offer full protection for only the first £35,000 of their savers' cash, Northern Rock depositors are covered by an unlimited 100 per cent guarantee from the Bank of England and the Treasury.

It applies not only to existing but also to new accounts and puts the Newcastle-based bank on a similar footing to the government's National Savings and Investment arm, which has traditionally been regarded as the most risk-free home for the public's savings.

Five months after Northern Rock became the most high-profile victim of the credit crunch, money might at last be about to flow back into the bank, as canny investors start to switch their savings into its high interest accounts.

Fee sparks road rage

The City banker's car of choice, the Porsche 911, has little in common with the tiny electric-powered cars occasionally seen darting through the traffic on London's congested roads.

But the German luxury car manufacturer has emerged as an unlikely ally of the electric car industry, as they unite in opposition to London mayor Ken Livingstone's latest plans to clamp down on drivers.

Livingstone introduced the congestion charge zone for vehicles entering central London five years ago, later extending the area further to the west and increasing the charge to its current £8 (€10.60) a day.

It remains hugely unpopular with motorists and claims that it has reduced congestion levels by as much as 30 per cent are widely disbelieved.

Now the mayor plans to clobber drivers of gas-guzzling 4x4 vehicles - the so-called Chelsea Tractors - and high-performance sports cars by hiking their daily charge to £25.

At the same time, low carbon emission motors such as the Renault Clio or Ford Fiesta will win an exemption, putting them on a par with electric vehicles.

Porsche has threatened to take legal action against the new charge, which is due to come into effect in October. The German company says the disproportionate increase for certain cars is unjust and will do little to help the pollution problem. It also claims the move will damage business in London, reducing its appeal to overseas executives.

Electric car manufacturers, meanwhile, are up in arms at Livingstone's proposals to exempt the most environmentally-friendly vehicles, including the Renault Clio and Ford Fiesta, from the charge. They accuse the mayor of undermining the emerging electric vehicle industry, as motorists will be left with little incentive to switch.

But the mayor knows he has a vote-winner in clobbering the Chelsea Tractor. Drivers of 4x4s are almost as unpopular in London as the congestion charge itself, although more because of their alleged disregard for other road users rather than their high carbon emissions.

Fiona Walsh writes for the Guardian newspaper in London