As if it wasn’t already obvious, today we got another vivid symbol of the turbulence on the high street.

Marks & Spencer, that traditional retail bellwether, has brought forward its summer sale by a couple of weeks. While analysts have speculated over what the move means for next month’s trading update, M&S argues that the change is more indicative of the economy as a whole than of its own performance.

“It’s in line with what the market is doing,” M&S shrugged in a statement.

They’re not wrong. Widely publicised research from PricewaterhouseCoopers found that 70% of high street retailers were holding sales last week. That’s up from 60% for the same week last year and just 40% in what are now looking like the halcyon days of 2009.

No wonder Thorntons is retrenching. Indeed, optimism is hard to find at even those riding relatively high.

Sainsbury’s finance chief John Rogers told delegates at Reuters’ Consumer & Retail Summit it was “very difficult to see light at the end of the tunnel”.

“There is a huge amount of pressure on consumers… and certainly will be for the next six months,” he said. It’s a sobering thought that the full impact of the government’s cuts has yet to be felt in terms of consumer spending.

If there’s one bright spot on the horizon, it must be the ginger bob of Mary Portas bouncing into Tesco to thrash out a rescue strategy for the high street. The Queen of Shops has her work cut out.