Retail giant John Lewis has reported profits down almost 15 per cent for the first six months of 2015.

John Lewis Partnership cited ''deep structural changes in the retail market'' after revealing its profits were down by 14.7 per cent to £81.9 million.

The group, which also owns Waitrose, said its commitment to competitive pricing, increasing pay and investment held back profits in the six months to July 30.

Chairman Sir Charlie Mayfield said the results were not linked to Brexit.

He said: ''We have grown gross sales and market share across both Waitrose and John Lewis, but our profits are down. This reflects market conditions and, in particular, steps we are taking to adapt the partnership for the future. These are not as a consequence of the EU referendum result, which has had little quantifiable impact on sales so far.

''Instead there are far-reaching changes taking place in society, in retail and in the workplace, that have much greater implications.''

Sir Charlie added that the uncertainty of leaving the EU will remain, with the full impact yet to become clear, and said trading pressures are expected to continue through this year and next.

After exceptional items, including a £25 million write-down on property assets that it no longer intends to develop, pre-tax profits in the period plunged 75 per cent to £56.9 million.

The write-down is linked to Waitrose where, following a strategic review, the group has scrapped plans to open seven stores and will instead be ''re-prioritising future investment spend towards existing stores''.

Waitrose managing director Rob Collins said: ''We are aiming to turbo charge out investment in our existing estate and an important part of that is hospitality.''

Sales at the upmarket grocer increased by 2.2 per cent to £3.2 billion in the first half, but like-for-like sales fell 1 per cent with the firm flagging a ''challenging'' market.

British supermarkets are embroiled in a bitter price war as they slug it out to win back market share and compete with German upstarts Aldi and Lidl.

Operating profit at John Lewis stores fell 31.2 per cent to £32.4 million and dropped 28.9 per cent to £96.3 million at Waitrose during the period.

Sales across the group were up 3.1 per cent to £5.3 billion, but its pension deficit ballooned 54.4 per cent to £1.45 billion as a result of historically low bond yields.

The partnership also said it is committed to better salaries for its staff, flagging that it intends to ensure pay remains ''well above'' the national living wage. As a result, additional pay costs for its lowest paid staff will be £33 million higher than if it complied only with the national living wage.

It anticipates this will mean employing fewer staff over time, although the reduction will be ''gradual''.