Victims of major disasters like the Grenfell Tower fire or the Hillsborough stadium crush will be given extra support in the immediate aftermath, under government plans unveiled on Monday.

Proposals for an independent public advocate are outlined in a broader consultation on improving the rights of victims. The Ministry of Justice will also consult on the creation of a “victims’ law” – a promise repeatedly made at party conferences – and upgrade waiting areas for victims and witnesses in courthouses.

The MoJ said an independent public advocate would help guide bereaved families through any investigative process after a disaster “so their voices can be heard at inquest”.

Although the title includes the term “advocate”, the official will not represent bereaved families at inquiries or inquests. The strategy document acknowledges there is “some potential for confusion”. A separate debate about how to fund lawyers for bereaved families at inquests is not yet resolved.

Other measures proposed include:

• Extending the unduly lenient sentence scheme to the court of appeal, enabling victims and the public to pursue requests for harsher sentences further through the court system.

• Boosting by 25% the number of registered intermediaries – communication experts who help vulnerable victims and witnesses give evidence in police interviews and trials.

• Reviewing the criminal injuries compensation scheme (CICS) and considering abolition of the pre-1979 “same roof rule”, which prevented payments from being made to victims who lived in the same home as their attacker.

The consultation, which will run until early December, follows criticism of the handling of victims of the Grenfell Tower fire last year and a damning report on the experience of relatives of the 96 Hillsborough victims.

In a foreword, the justice minister Edward Argar said: “It is clear there remain serious concerns about how far the voices of the bereaved are heard, and how far they are supported in fully understanding and participating in the investigatory process.”

Theresa May said: “Nothing can take away the distress and trauma of being a victim of crime, but ensuring people get the support they need as they rebuild their lives is vital. How we support victims is fundamental to a caring society, and in recognition of that we are taking steps to enshrine their rights in law for the very first time.”

The justice secretary, David Gauke, said: “Many of us will be lucky enough to not have to encounter the justice system as a victim of crime, but those who do must not also become a victim of the process.”

Helen Newlove, the victims commissioner for England and Wales, said: “This is a timely focus on the needs and rights of victims, and is a major step forward towards ensuring they receive the care, support and justice they deserve.

“Victims consistently tell me that they feel their status in the criminal justice system is not comparable with that of the offender. As victims commissioner I have long been calling for a victims’ law to ensure that the rights of victims are central to the delivery of our justice system.”