This petition was rejected

The Government e-Petitions Team gave the following reason:

Making a false allegation of a crime may already in some circumstances lead to a jail sentence - for example, if someone is found guilty of perverting the course of justice. In other cases, people who are accused of making false accusations may be prosecuted for wasting police time.

It is not therefore clear to us how you would like the law to be changed.

You may find this guidance from the Crown Prosecution Service helpful:

http://www.cps.gov.uk/legal/p_to_r/perverting_the_course_of_justice_-_rape_and_dv_allegations/