Researchers at the University of Manchester say Christians are the least likely among religious groups to identify themselves as British but the most likely to identify themselves as English.
In an analysis of responses to the 2011 Census question on national identity, the researchers found that three-fifths of the English population do not identify with a British national identity, while ethnic minority and non-Christian faith communities are more likely to.
Just 15% of Christians chose to identify themselves as British only. Most Christians (65%) identified themselves as English only.
Jews were also much more likely to identify themselves as English only (54%).
Conversely, nearly two-thirds of Sikhs (62%) and over half of Muslims (57%) and Hindus (54%) described their national identity as British only.
Buddhists were most likely to report their national identity as "Other" (42%).
Among ethnic groups, those most likely to report only a British national identity were Bangladeshis (72%), Pakistani (63%) and Indian (58%).
White British and mixed ethnic groups were more likely to choose English rather than British as their national identity (72% and 47% respectively).
The study was led by Dr Stephen Jivraj and Professor Ludi Simpson at the University of Manchester's Centre on Dynamics of Ethnicity.
They conclude that the findings call into question the Coalition Government's emphasis on ethnic minorities and migrants embracing 'British' values.
Dr Jivraj said: "Indeed, the distinction between British and English identities continues to confuse not only tourists, but policy makers – but it's something we all need to understand more fully.
"If you believe what you read in the newspapers, Muslims are less likely to feel British than anyone else. In fact, the opposite is true.
"For many non white residents, including Muslims, this feeling of Britishness is probably partly a result of the citizenship process: they are surely less likely to take their Britishness for granted.
"Our findings are at odds with the present and previous Government's emphasis on encouraging ethnic minorities and new migrants to accept 'British' life and 'British' values."