The grocery market grew by 6 per cent in the 12 weeks to December 28 but Tesco's market share has fallen 0.6 percentage points compared with a year ago, according to figures from TNS.

Tesco’s market share fell from 31.3 per cent a year ago to 30.7 per cent. Asda and Morrisons' market share climbed 0.2 and 0.4 percentage points respectively, lifting Asda’s share to 16.9 per cent and Morrisons' to a record 11.9 per cent.

Sainbury’s share held firm as its Basics range helped it balance its positioning between the premium and value ends of the sector. Waitrose’s shareholding fell from 3.9 per cent to 3.7 per cent as premium retailers came under pressure.

At the discounter end, Aldi notched up a record 3.2 per cent market share.

In comparing the four weeks to December 28 and the four weeks to November 30, Sainsbury's and Waitrose both outperformed the market and premium private labels outshinied value-based counterparts over Christmas.

Grocery price inflation fell to 8.3 per cent in the 12 weeks to December 28 – the third successive drop from its peak of 9.3 per cent, which came in the 12-week period ending October 5.