(Adds traders' comment, background)
LONDON, Sept 11 (Reuters) - Sterling rose to a three-and-a-half-week high against the euro on Monday, helped by speculation that the Bank of England may sound more hawkish on interest rates this week in defence of the currency.
The pound hit a five-week high against the dollar last Friday after better than expected manufacturing numbers, and market data also showed a month-long build up of speculative bets against the currency stalled in the week to last Tuesday.
That does not represent a full quelling of the unease that has gathered over sterling in the first months of Brexit negotiations.
But it comes ahead of a Bank of England meeting on Thursday that some analysts and traders believe could show it is increasingly worried about the weak pound's effect on inflation.
"The firmer growth developments (last week) should provide more confidence to the BoE that economic growth is still holding up relatively well since the Brexit vote," said Lee Hardman, a currency analyst at Japan's MUFG.
"We expect the BoE to reiterate this week that the market is underestimating the scale of rate hikes likely in the coming years, although they will likely stop short of signalling a rate hike is imminent this year."
Against the euro, that mood helped the pound strengthen to less than 91 pence per euro for the first time since Aug. 18 , gaining 0.2 percent on the day against a broadly weaker euro.
It dipped less than 0.1 percent to $1.3188, a third of a cent off five-week highs hit after a stronger batch of manufacturing data on Friday.
"The noise (around sterling) has not gone away and I'm sure if we get to the end of this week at highs then next Monday will look different," said Richard Benson, co-head of portfolio investment with currency managers Millennium Global in London.
"But if sterling is going to have a good week then this is it. Cable (dollar rates) may prove sticky but euro sterling could head towards 90 pence." (Writing by Patrick Graham; Editing by Saikat Chatterjee and Mark Trevelyan)