Two in five of more than 13,000 NHS doctors cited the longer-term impact on patient clinical demand as their top concern relating to the coronavirus pandemic, according to polling by the BMA.
A total of 56% of respondents to the poll said that care for patients without COVID-19 symptoms had worsened as care for those with confirmed or possible COVID-19 was prioritised.
The findings come just a week after GPonline revealed that some patients had yet to be offered appointments more than a month after being referred on the two-week urgent cancer pathway around the time that the UK went into lockdown.
Referrals on the two-week pathway have also dropped sharply, along with A&E attendances and patients attending hospital for heart attacks - as government polling found that millions of patients are avoiding seeking help from their GP during the pandemic.
Health charities have also warned that suspension of some routine GP services during the pandemic could lead to a 'future crisis' if control of conditions such as asthma and COPD deteriorates.
BMA chair Dr Chaand Nagpaul said the latest survey findings showed that the needs of patients without coronavirus symptoms were being 'neglected' - and urged the health service to plan ahead for a future surge in demand.
'While all parts of the NHS have rallied around in a bid to meet the immediate rocketing demand caused by the COVID-19 pandemic, these findings bear out the fears held by many doctors that parts of the health service - and most importantly the needs of patients more widely with non-COVID illness - are being neglected.
'This means many ill patients are not getting the care they so desperately need now - and crucially, risking their conditions getting worse and with some maybe even dying as a result. Once this current situation eases, it is highly likely that there will be a sudden spike in demand, from patients with far more acute illnesses, caused by a delay in timely treatment. It is vital that the NHS plans for this now.'
He added: 'Before any lockdown measures are eased, the government has rightly insisted that the NHS must be able to cope. These results clearly show that this is not just about Covid, but also a potential surge in other patients, who may have put off accessing healthcare or, indeed had their treatment deferred.
'Crucially the government must set out a clear and tangible plan of how the system will have capacity both for the ongoing demands of the pandemic, as well as resuming services for those patients whose care has effectively been frozen.'
NHS chief executive Sir Simon Stevens set out last week plans to begin to restore routine NHS services over the coming weeks in the second phase of the NHS response to coronavirus. GP practices have been asked to provide weekly virtual care home rounds as part of the plans - in a move heavily criticised by the BMA.
The government has said the UK is now 'past the peak' of the outbreak. A total of 28,446 patients have now died from COVID-19 according to official figures for 2 May that include more than 4,000 deaths outside hospitals.