Upmarket supermarket Waitrose reported a 12.8 per cent sales rise last week as warm weather over the Bank Holiday drove sales, it has been announced today.

For the week to May 11th 2013, the grocer saw strong trade thanks to summery weather that beat the cool temperatures over the same period last year and in recent weeks as warm-weather food sales grew.

Ice cream sales leapt 31 per cent on last year while sales of tuna and barbecue meats increased 77 per cent and 48 per cent respectively.

Salads and dressings saw sales rise 22 per cent each while soft drinks sales climbed 23 per cent and cider sales shot up 41 per cent on last year.

Such strong sales are propelling bricks & mortar growth at the chain, which opened its relocated store in Oakgrove, Milton Keynes last week and will open its eighteenth Welcome Break Waitrose on Junction 13/14 of the M5 next week, as these format shops saw sales increase 17 per cent on last year.

Online sales continue to build momentum, the grocer noted, up 41 per cent on the same week in 2012, as The Telegraph reported that the grocer is to introduce concierge desks in stores allowing shoppers to make online orders and collect products purchased online.

Such a move seeks to respond to evolving shopping habits as the online grocery sector becomes increasingly competitive.

Earlier this week, Waitrose‘s Managing Director Mark Price warned that the grocer may veto a deal between online grocer Ocado and rival Morrisons, stating that he would “never knowingly sign a contract with Ocado that agreed to them working with another retail competitor”.

However, earlier today, the pair confirmed that the deal will go ahead as Morrisons belatedly enters the fiercely competitive online grocery sphere.