The traditional dialects of Bedfordshire, Huntingdonshire and south Northamptonshire are closer to Received Pronunciation than any other dialects in Britain. This is because the upper-class who migrated into London during the 15th century were mostly from the counties just north of London.
However, there are still a number of differences between their dialects and R.P.:
This area traditionally used /aː/ in words where an was followed by /f/, /s/ or /θ/. Younger speakers in the area are more likely to use the R.P. /ɑː/.
The isogloss for the vowel in cup, strut, such, etc. is another traditional north-south marker, but the isogloss is slightly further south for this. Much of the area uses /ʊ/. Some parts of this area, such as Peterborough, would use the southern pronunciation for "bath" but the northern pronunciation for "suck".
The TRAP vowel (corresponding to RP /æ/) is realised as [a], as is the case in all of England except the south-east and East Anglia.
In common with the south-east, the vowel in about, pound, sound, etc may be [ɛʊ] rather than /aʊ/.
It is common for residents of this area to pronounce the -shire in county names as /ʃɪə/ rather than the more common /ʃə/, which is used in the Oxford Dictionary.
In some areas, an /ai/ can turn into an [oi] sound. For example, nineteen ninety-five would be said as noineteen noientee foive.