The plans from NHS England would see new waiting time targets set for the initial assessment of patients, "rapid" treatment of the most seriously ill including those with mental health conditions, and an average time for all patients replacing the four-hour standard.
When the latest A&E waiting time figures were announced last month Professor John Appleby, the Nuffield Trust chief economist, said: "This situation has a serious impact on hundreds of thousands of patients and will be demoralising for many staff".
The pilot schemes aim for mental health patients attending A&E in crisis to receive emergency treatment within an hour.
NHS England may scrap four-hour A&E wait target
"When the four-hour target was introduced in 2004 it helped to significantly reduce the lengthy waits faced by many patients".
NHS England said now one in five admissions to A&E happen in the final 10 minutes before the four-hour deadline and said hospitals are focusing on meeting targets "rather than what is the best approach for each patient". It has not been met nationally since July 2015. However, the review makes no proposal as how long this should take.
NHS England stresses the measures are still proposals and implementation will be subject to the outcome of the trials.More news: Iran's President Hassan Rouhani hails 'special' ties with Iraq ahead of visit
Baroness Delyth Morgan, chief executive of Breast Cancer Now, said: "The current "two-week wait" for breast cancer has been hugely successful in transforming the experiences of people referred to a specialist to investigate their symptoms".
"Being referred with breast symptoms can be an incredibly worrying time for thousands of women and their families, and it's critical that they are given answers and can begin treatment or be given peace of mind as soon as possible".
Healthwatch national director Imelda Redmond said: "What shapes people's experiences of A&E is often not how long they wait, but the quality of care they receive and how that care is delivered".More news: DUP To Vote Against Amended Brexit Deal
"However, it's hard to see exactly how it will be possible to meet these new more stringent standards without more staff - or they would already be taking these sensible measures". If the NHS is to focus on ways to save lives that is what we should be measuring.
The decision to ditch the four-hour target is likely to be the most controversial measure.
"The reality is years of austerity, understaffing and wider cuts have left our A&Es overcrowded and in crisis".More news: Felicity Huffman, Lori Loughlin among dozens charged in $25m USA college scam
The NHS review of clinical standards confirms that the NHS's flagship performance marker may be scrapped with changes to A&E targets accompanied by new plans for waiting times for cancer, mental health and planned operations.