Controversial powers used by security services to collect large volumes of data are not "inherently incompatible" with human rights laws on privacy, MPs and peers have said.
So-called bulk capabilities are "capable of being justified", the Joint Committee on Human Rights concluded as it published a report on the Government's proposed surveillance laws.
Bulk powers are among the most controversial tactics set to be covered by the Investigatory Powers Bill, dubbed the "Snoopers' Charter".
The Government has previously disclosed that they have played a part in every major counter-terrorism investigation in the last decade.
The powers cover a range of techniques used by GHCQ, MI5 and MI6 to acquire information in large volumes. Data is then used to generate intelligence about threats that cannot be obtained by more targeted means.
The committee's report said: "On the current state of the ECHR (European Court of Human Rights) case-law, we do not consider the bulk powers in the Bill to be inherently incompatible with the right to respect for private life, but capable of being justified if they have a sufficiently clear legal basis, are shown to be necessary, and are proportionate in that they are accompanied by adequate safeguards against arbitrariness."
Overall, the committee welcomed the Bill as a "significant step forward" in human rights terms.
Its report added that the proposed laws could be improved to "enhance further the compatibility of the legal framework with human rights".
Although it recognised the value of "thematic" warrants, the committee said it considered the wording of clauses concerning the subject matter of targeted interception and equipment interference warrants to be "too broadly drafted".
It recommended that the Bill be amended to ensure the description in the warrant is "sufficiently specific" in order to "prevent the possibility of large numbers of people being potentially within the scope of a vaguely worded warrant".
Further safeguards in relation to MPs' communications, lawyer-client confidentiality and journalists' sources were also suggested.
Committee chairwoman Harriet Harman said: "The Bill provides a clear and transparent basis for powers already in use by the security and intelligence services, but there need to be further safeguards.
"Protection for MP communications from unjustified interference is vital, as it is for confidential communications between lawyers and clients, and for journalists' sources, the Bill must provide tougher safeguards to ensure that the Government cannot abuse its powers to undermine Parliament's ability to hold the Government to account."
Earlier this year, the Government made a number of revisions to the Bill after three parliamentary inquiries raised concerns. The proposals aim to bring myriad surveillance powers under one legal umbrella.
A Home Office spokeswoman said: "We welcome the report by the Joint Committee on Human Rights.
"The Government has always been clear, we will listen to the constructive views of politicians from all sides of the House to ensure the passage of this important Bill.
"We have encouraged rigorous scrutiny of the Bill, which responds to three independent reports all of which recognised that new legislation in this area is absolutely essential.
"We published a draft Bill that was subject to pre-legislative scrutiny by three Parliamentary committees and we have listened closely to detailed and productive points made during Commons Committee Stage.
"It is right that any further detailed discussion and debate should be on the floor of the House at Report Stage."