The APPG on Nursery Schools and Nursery Classes will examine the importance of nursery education, how high-quality provision can be best achieved and measured, and whether structural changes could benefit providers.
The APPG is chaired by Conservative MP Graham Stuart, a former chair of the education select committee, and co-chaired by Labour peer Tessa Blackstone.
The launch of the APPG follows figures from Ofsted last November showing that the number of childcare places provided by nurseries fell by 11,000 last year.
Beatrice Merrick, chief executive at Early Education, welcomed the new APPG.
"At a time when many politicians are talking only about 'childcare', we welcome this APPG's focus on the role of high-quality nursery education to give young children the best start in life," she said.
"We look forward to working with the APPG to build public understanding of the importance of maintained nursery schools in supporting children, especially those with special educational needs and disabilities, and children from disadvantaged backgrounds.
"Despite their extraordinary record in offering the highest-quality education, nursery schools are closing across the country, from Bedfordshire to Bolton, and we must reverse this trend before it is too late to rebuild this specialist cadre of expert staff."