The employee-owned company, traditionally seen as a bellwether of the UK retail sector but which has outperformed competitors for over a year, said on Friday sales at its 28 department stores and two "at home" stores rose 7.2 per cent to £59.5m in the week to 9 October.
That compares with growth of 13.9, 15.1 and 11.7 per cent in the previous three weeks respectively.
"The tube strike on Monday (4 October) in London, added to the relatively good weather compared to a year ago, contributed to lower footfall in our shops," said buying and brand director Peter Ruis.
"However, the fantastically strong John Lewis Direct (Internet) sales (up 46 per cent) must give us confidence that consumer spending is still strong despite the potential impact of the upcoming public sector cuts," he said.
A survey on Wednesday said consumer confidence fell in September to its lowest level in a year, while one on Tuesday said retail sales growth halved in the same month, as uncertainty ahead of the government's October 20 review made shoppers nervous.
John Lewis also owns the 234-store Waitrose supermarket chain. Here sales rose 9.6 per cent to £92.8m underlining its status as one of the UK's fastest growing grocers.
Commercial director Mark Williamson said the outcome was boosted by the firm's "Brand Price Match" campaign, where 1,000 branded lines are price matched with Tesco, Britain's biggest retailer.
Sales were also boosted by consumers eating in on Saturday to watch popular television shows "X Factor" and "Strictly Come Dancing," with sales of pizza up 30 per cent and Italian ready-meals up 23 per cent.