Vulnerable adults will be protected in the same way as children by the next general election, the Liberal Democrat social care minister Paul Burstow has said.
Police, social workers and medical staff are currently obliged by law to investigate where cases of child abuse have gone undetected.
But there is no legal requirement on local authorities, which oversee the investigatory panels, to provide the same protection for vulnerable adults.
With cuts to local authority grants from central government, town hall officials are concentrating what finances are available on the services they have to provide, Mr Burstow said.
This means that fewer councils are investigating cases when the elderly or disabled have been mistreated in care.
Mr Burstow told the Liberal Democrat conference in Birmingham that it is estimated there are 342,000 people over 65 who have suffered varying degrees of abuse.
“At the moment there are not the same safeguards in law as there are when it comes to child protection, or indeed the protection and welfare of animals,” he said.
“I can tell you, conference, that this government will do what Labour never did - we will put on a statutory basis adult safeguarding during the lifetime of this parliament.”