The Electoral Commission is to be probed by the government's standards watchdog amid concern about vote fraud and low election turnouts.
The Electoral Commission monitors the conduct of political parties.
The Committee on Standards in Public Life is worried about the lack of public trust in the democratic process.
The Electoral Commission was set up in 2000 to boost engagement in politics and ensure electoral fair play.
But its call for all-postal ballots to be banned was rejected by ministers ahead of last year's general election.
The Standards committee will examine whether the Commission is sufficiently independent of government, accountable to Parliament and whether it has the right powers.
The inquiry comes in the light of a number of high-profile court cases over postal vote fraud and questions over political parties exploiting loopholes in funding rules.
Standards committee chair Sir Alistair Graham said: "Confidence in our democratic process is vital to enable people to re-connect with politics.
"At a time when there is a lack of trust in the system, the Electoral Commission really has a very important role to play in sustaining the health of the democratic system.
"We just want to make sure it is fully equipped to do the job."
The Electoral Commission oversees the registration of political parties, and monitors donations to registered political parties and election spending.
It also manages referendums and is responsible for promoting voter awareness and public involvement in the democratic process.
The inquiry will involve a series of public hearings throughout the UK held later this year as part of a consultation on the issues being examined.
A consultation paper setting out the questions to be asked about the Electoral Commission was published on Thursday by the Committee on Standards.
Details of the inquiry and how to submit evidence are published on the Committee's website, at www.public-standards.gov.uk.
The government's own plans for a shake-up in the electoral system - suggesting supermarket and text message voting - came under fire in debate this week in the Lords.