Mono: Dispatcher.Invoke not implemented - Looking for workaround

Question

I would like to use the method Dispatcher.Invoke in mono. Unfortunately it throws a System.NotImplementedException.

Question:

What would be a workaround?

Note: I am using Mono 4.0.1 with Xamarin Studio 5.9.3 on OS X version 10.10.3.

Update:

As probably no general workaround exists here an example of the code I work with.

The call I have in my case is:

Dispatcher.BeginInvoke(new Action(() => {
    execute(parameters);
}));

with execute just being a member variable of type Action

readonly Action<T> execute;

So I am interested to execute lambda statements on another thread.