Wouldn't work in the US. If you're over fifty and in need of a job, fogeddaboudit. Working to seventy would mean holding a job until you're seventy in an era where there is no loyalty by the company to the employee, hence no loyalty by the employee to the company. Britain must be a different fish.
There's a distressing age discrimination in the US. People are forced (or strongly encouraged) to retire early. When they run for their lives (er, retire), they find that they'll never regain their former earning power. It's an adjustment. The younger folk will force us off the rolls, and then we'll find that our ability to compete in the workplace is sadly diminished.