Britain's service-sector growth rose to a 10-month high in August, with the rate of expansion accelerated by market output and new orders.
The Markit/CIPS purchasing managers' index (PMI) rose from 59.1 to 60.5, the biggest monthly rise since October 2013, which, Markit said, was attributable to high profits in new business and positive forecasts by service companies.
"The sustained elevated PMI readings suggest we will see another quarter of strong economic growth in the third quarter, similar to the 0.8% expansions seen in the first two quarters of the year," said Markit chief economist Chris Williamson.
Williamson, who said the sustained recovery will be well received by policymakers calling for higher interest rates, also warned that the economy was still somewhat over-reliant on the services sector.
"Worryingly, the August data show that the economy has become increasingly dependent on the vast service sector as a driver of the continuing recovery," explained Williamson.
"While the services and construction sectors are set to grow by at least 1% each in the third quarter, manufacturing looks to be faring less well."
Markit said capacity in the services sector remained under pressure even though companies continued to recruit additional staff, while ongoing competitive pressures, which placed a restriction on the pricing power of service providers, were less competitive.
Williamson also said the service sector remained reliant on domestic demand, which could be limited if interest rates were to rise.
"The worry is that growth remains too dependent on the domestic economy, raising the risk that higher interest rates will derail the upturn. Any hopes of a rebalancing towards exports have been dealt a blow by the escalating Ukraine crisis," he explained.
"Dovish policy makers will worry that the Ukraine crisis will also filter through to a significant slowdown in services and construction. Some impact is already evident, with growth of new orders and employment moderating in all three sectors in August."
In August, the factory output index fell to 53.7 from 56.4, as growth slowed down for the fourth consecutive month, while the sector registered the smallest monthly improvement since April 2013.
Analysts said recent results should lead to gross domestic product (GDP) growth coming in line with predictions.
"UK data remain robust, growth looks set to remain above trend and the fact that the services and construction PMIs are the areas of strength suggests the recovery remains very much domestically driven," said Dominic Bryant, market economics analyst at BNP Paribas.
"This reflects the stance of policy; interest rates at 50 basis points are well below neutral, which looks increasingly at odds with economic developments. A 25 basis points hike by the Monetary Policy Committee in November is therefore more likely than the market thinks."