The trouble is, before they get to quiz the heath secretary, visitors scrolling through the prime minister's website are likely to come across a petition calling for Ms Hewitt to be sacked.
Led by a Dr Ben Taylor, website visitors have taken the invitation to 'use our popular online petition system to make your views heard' at its word - by petitioning Mr Blair 'to remove Patricia Hewitt from the office of health secretary'. Almost 600 people have so far added their name to the call.
Dr Taylor, warming to his theme, says: 'Common consent among frontline healthcare staff suggests Ms Hewitt is the worst health minister in living memory.
'She has lost the confidence of NHS staff on the shop floor and seems to have no idea about what is going on. Her reforms have been draconian and NHS morale is at rock bottom because of them.'
The number of voters taking part in Ms Hewitt's webchat today will probably not be revealed, but they will 'have the chance to quiz the health secretary about the future of the UK's public services' for an hour.
It's all part of the government's policy review of almost everything, announced by Tony Blair in October last year.
Labelled 'Pathways to the Future', the review stretches from 'Britain and the world', to 'the role of the state', 'economic dynamism', and, as promised, 'it won't take place behind closed doors'.
Ms Hewitt's webchat is just the beginning: later this month 100 members of the public will take part in forums scrutinising each area of the policy review.
The government says it will work in a similar way to the Your Health, Your Care, Your Say white paper consultation.
When the policy review was announced, the prime minister's official spokesman said Ms Hewitt believed it would 'strengthen the public's faith in democracy'.
And democracy seems to coming to her aid on the Number 10 website, where she will be questioned today. Although 590 people have signed the petition calling for her head, more than 3,000 have signed up to support a call for Mr Blair to stand on his head and juggle ice cream.