Tesco chief Philip Clarke has vowed that the grocer’s strategy will ultimately lead it to success despite suffering a 1.5% slump in UK like-for-like sales in its third quarter.

Clarke said Tesco, along with the other major grocers, is feeling the pressure of both the discounters and upmarket grocers such as Waitrose but added: “We will succeed because we will become multichannel.”

He said: “Customers want that seamless shopping experience now. Over time it will be clear who has made the long term changes needed to meet that demand.”

Clarke pointed to sales of its Hudl tablet as an example of Tesco’s multichannel strategy. “We’ve sold 300,000 so far and expect to double that over Christmas. We can’t make them fast enough. And it is an important part of our multichannel future.”

He said Hudl 2 would be unveiled next year.

Tesco also blamed its performance on “weaker growth seen in the UK grocery market as a whole”. It said consumers are still managing the effects of an unprecedented period of declining real incomes and a higher cost of living, and pointed out the average spending power of a typical UK household is around 10% below its 2007 peak.

Clarke said: “We are in the middle of a retail revolution and in one of the toughest consumer markets for a generation.”

He said the store refresh programme was on course and “has shown good uplifts”. He said Tesco will “pick up the pace” on any new innovation once it is proven. He gave the example of scan as you shop. “That was in four stores in January 2012, it is now in its 204th store,” he said.

Clarke added that Tesco would not be forced to cut prices – which has been called for by some analysts – and said the grocer would continue to “do the right thing for the customer”.

He said: “I will not trade long-term health for short-term help.” He also said he was comfortable with its 5.2% operating margin, but it is not “set in stone”.

Tesco also suffered like-for-like declines in all its international markets. Like-for-likes in Asia were down 5.1%, while in Europe like-for-likes were down 4%. Ireland suffered the biggest fall, falling 8.1%.

Clarke said its international markets all have “long term potential” but did not rule out further sell offs. He said improvements have been seen in Poland and Turkey where it has made changes to its business.

In Ireland, he said customers have been under “extraordinary pressure” for a long time and the big change has been the “high level of vouchering including Aldi for the first time”.

Clarke said Christmas in the UK will be “very competitive for all retailers”. He said he expects the same trends to continue with “customers seeking value”.