The plugin seems to conflict with the standard plugin.

Is there a way so that both can be installed?

Exception: java.lang.IllegalArgumentException: CloverPublisher is ambiguous; matches both org.jenkinsci.plugins.cloverphp.CloverPublisher and hudson.plugins.clover.CloverPublisher
Stacktrace:

javax.servlet.ServletException: java.lang.IllegalArgumentException: CloverPublisher is ambiguous; matches both org.jenkinsci.plugins.cloverphp.CloverPublisher and hudson.plugins.clover.CloverPublisher
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:615)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:658)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:241)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:573)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:658)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:487)
at org.kohsuke.stapler.Stapler.service(Stapler.java:164)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:45)
at winstone.ServletConfiguration.execute(ServletConfiguration.java:248)
at winstone.RequestDispatcher.forward(RequestDispatcher.java:333)
at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:376)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:95)
at hudson.plugins.greenballs.GreenBallFilter.doFilter(GreenBallFilter.java:58)