Just 36% of GP partners responding to the latest GPonline opinion poll said they had already formally signed up, with only a week to go until the deadline.
A further 32% of the 152 GP partners who took part said they planned to sign up, while 9% said they would not - and the rest were unsure.
Scores of practices across England are understood to have informed their CCGs that they do not intend to take part in the network DES, which governs practices' involvement in primary care networks (PCNs) - a key plank of the five-year plan for the NHS launched last year.
BMA executive committee member Dr Farah Jameel said in a recent update that figures from NHS England showed that 74 practices had already told their CCG they had decided against taking part in the network DES.
Overall, NHS England believes 96% of practices have either signed up or plan to do so - but PCN plans have been deeply controversial, with some LMCs warning that the workload involved in specifications within the network DES and the available funding will leave practices out of pocket.
LMCs have warned that for some practices the risks of signing up may outweigh the benefits - despite a huge tranche of primary care funding set to be delivered through networks.
A total of £1.8bn in funding is to be delivered through PCNs by 2023/24 - far more than the £1bn increase in core funding due over the same period.
The majority of GPs look likely to sign up, but many will do so with significant reservations and in the knowledge that they can back out in 2021 - or sooner if NHS England decides to change the terms of the network DES.
Some GPs responding to the poll said they were signing up, but without enthusiasm. One said: 'I don't want to sign up but dropping the other network practices in it at this time is not fair - on which I guess the powers that be rely.
'There is little point one practice opting out - it would have to be whole networks, which I hoped would happen but some remain determined to make it work. I've been around longer and suffered too many such reorganisations.'
Another partner said: 'We don't want to sign, neither do the rest of the PCN. But feel we have been left with no option.'
Another GP expressing his ambivalence over the deal wrote: 'There is a lot of money attached, so we probably will do it, but there is still that strange combination of ambiguity and micromanagement in which NHS England seems to excel.
'They are like what in the charitable sector are called restricted funds: your hands are tied as to how you spend them and it does not feel like freedom.'
One GP not planning to sign up said simply: 'It undermines general practice. Makes practices liable for other practices and does not provide enough money to do the work.'
Respondents highlighted requirements to support care homes in particular as a key concern. One GP wrote that her practice would sign up, but only because it felt it could not afford to lose out on potential additional funding. 'The main reason is financial - we will be taking a loss of earnings due to COVID-19, however lots of concerns over care home provision for our surgery and being forced to cover the disengaged surgeries as part of our PCN.'
Another said: 'We have not had the full discussions as yet within our PCN. We were not happy to sign up previously and now we have been distracted by COVID-19 work. The new DES specs need looking at as I don't think we should take for granted that we are accepting the need to sign up.'
NHS England warned last week that it would not allow an extension of the deadline for practices to sign up to the DES because GPs had had 'plenty of time' to decide.