Andrew Pinder, who has the job of getting UK government online, is stepping down.
The e-Envoy will leave when his contract ends in spring 2004.
Mr Pinder has been overseeing the process of making sure that government services are online by 2005.
He took up the Cabinet office post in 2001 but his exit spells uncertainty for the Office of the e-Envoy (OeE).
As Mr Blair's target of getting people, businesses and government services online by 2005 gets nearer, the OeE's future has increasingly been under scrutiny in recent months.
The OeE has been responsible for a number of projects within the government's e-government strategy.
These have included finding ways of ensuring people can participate more in politics and democracy using digital channels like TV and the internet.
A spokesperson from the Cabinet Office told BBC News Online the future of the e-Envoy role would be decided in due course.
"The government is focused on driving forward its e-agenda. We will consider how best to continue this drive when Andrew Pinder's contract comes to an end", she said.
There is some speculation however, that the OeE could play some kind of role as part of an overhaul of the government's communications strategy currently under review.
An interim report looking at the effectiveness of how the government communicates - including electronic communication - in light of the Hutton Inquiry, was published last month. The full report comes out at the end of the year.
Some proposed changes include the appointment of a new Permanent Secretary for Government Communications.
However, the Cabinet Office spokesperson said they were not pre-empting the outcome of the report. She said any role of the OeE as part of the proposals would not decided until the review is reported in full.
Under the proposals, the Secretary would head the central civil service communications unit and would be responsible for media and press communications, as well as "Strategic Planning and Development".
Part of the responsibilities would also be to make sure there is better "two way communication" between the general public and the government, as well as improved resources for government websites.