The service sector grew faster than expected in September, bolstering expectations the Bank of England will raise interest rates before the end of the year even if not this week.
The services business index from the Chartered Institute of Purchasing and Supply/Royal Bank of Scotland rose to 57.0 in September from a nine-month low of 56.7 in August.
Analysts, who had forecast a pullback to 56.5, were also wrong-footed by a stronger than expected manufacturing survey earlier this week.
"Along with improving manufacturing output, this shows the UK economy is entering the third quarter in very strong health," said Gavin Redknap, economist at Standard Chartered.
Business expectations rebounded strongly after hitting their lowest in over three years in August, when the BoE Monetary Policy Committee delivered an unexpected quarter point interest rate hike to 4.75 per cent and thousands of air passengers were stranded after security alerts at UK airports.
The survey also offered encouraging signs on inflation with weaker oil prices putting downward pressure on input and output price growth.
Pundits reckon there is around a one in three chance of a rate rise today and, if the decision is for no change, a more than 80 per cent chance of an increase in November.
Any reading above 50 implies expansion and the service sector, which accounts for around three-quarters of the economy, has registered growth for the past 42 months.
"There is much to take encouragement from," said RBS Group chief economist Andrew McLaughlin.
"The future expectations component indicates broad-based confidence among UK companies with no discernible dampening effect from the August rate hike."
The employment index pushed up to 54.2 in September from 52.8 in August and has been in expansion territory for 38 months.
Input prices continued to increase but at a much slower pace than in August when rising energy costs lifted the index to its highest in the decade-long history of the survey.
The average prices charges component also eased from August's near six-year peak but still indicated a robust rate of inflation.
"On balance, the data leave open the option of a November rate hike and few companies will complain if demand remains this strong," claimed Mr McLaughlin.
The Royal Institution of Chartered Surveyors has urged the MPC not to be swayed by an over-inflated analysis of the housing market.