The work highlighted NHS figures that, he said, show a decline in GP services under conservatives.
Figures show that in October there were six million GP consultations – 31 million – for which patients had a wait of more than two weeks.
Labor said "it is yet another damning evidence of the crisis the NHS is in after a decade of conservative cuts."
Conservatives responded by highlighting their plans to hand over 50 million more consultations by 2024-25, if elected.
The NHS Digital numbers do not distinguish between patients who were content to wait for a more routine meeting at the local surgery and those who wanted a more immediate appointment and couldn't get one.
The latest data from the NHS Digital show that 2.45 million patients waited between 15 and 21 days in October to see a general practitioner or other clinician, which was 8.3% of the total number of consultations, compared with 8% in October 2018.
Another 1.69 million waited between 22 and 28 days for a GP appointment, while 1.66 million waited over 28 days.
In both cases, there was an increase in the percentage of affected patients compared to October last year.
The total number of consultations increased to 30.8 million in October 2019, from 29.7 million in the same month last year.
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"You can't make an appointment" media caption – patients and staff in a doctor's office
Shadow Health Secretary Jonathan Ashworth said: "More families are struggling to get a doctor's appointment after the Conservatives allowed the number of family doctors in our communities to fall."
He said the Labor Party had a £ 40 billion bailout plan to invest in general practice, where more doctors would be recruited and would provide millions more medical appointments.
The paper also cited new GP workforce figures in England, which show that the number of fully qualified GPs in the general practice had fallen by more than 1,600 since September 2015 to just under 27,000 in September this year.
The conservative government promised in 2015 to add 5,000 GPs by 2020.
However, Conservatives refer to a different measure, which includes qualified training for general practitioners – this group has increased by 400 since September 2015.
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Health Secretary Matt Hancock said: "It is great news that we have seen an increase in the number of general practitioners and that more people are receiving an appointment the same day or the next day.
He said: "A conservative majority government will create over 6,000 general practitioners and deliver 50 million more medical appointments – to ensure everyone can get the care and treatment they need faster."
The Labor Party has promised, if elected, to increase the number of GP seats in England from 3,500 to 5,000 a year.
Conservatives say they would increase training vacancies to 4,000 and recruit more GPs from abroad, along with measures to increase retention.
Liberal Democrats say they first identified on Thursday – from NHS data itself – that the number of doctor's offices has dropped to a record.
The party accused the conservatives of not fulfilling their promises in GP numbers.
He wants to close the GP deficit in five years with more training and what they say will be easier for foreign recruitment if the UK stays in the EU.