SQL: Temp tables and script failing on second use, but works on the first

I have a script that makes use of temp tables. When I disconnect from the server, connect, and run the script, it works as expected. If I run the same script twice, it works the first time, and then on the second time, complains that;

Column name or number of supplied values does not match table definition.

I believe I am dropping the table explicitly below. I also have at the start of the script a handful of extra drop table commands for the temp tables as good measure. How can I ensure the temp tables are removed so the procedure is repeatable?

-- create table of differences
drop table if exists #TMP;
select A.*,'table A' TABLE_NAME INTO #TMP from  #compare1 a
full outer join #compare2 b on a.hash = b.hash
where ( a.hash is null or b.hash is null );

INSERT INTO #TMP -- FAILS ON THIS LINE; only one the second try!
select B.*,'table B' from  #compare1 a
full outer join #compare2 b on a.hash = b.hash
where ( a.hash is null or b.hash is null );

Answer

Drop the table at the end of the script not at the beginning.

If you must drop it at the beginning put a GO after the drop table if exists so it runs in its own batch before trying to compile the rest of the script.

Also consider using a more specific name than #TMP – it looks like there must be another instance of that table name created in a parent scope that is visible when compiling the batch and causing the error. (or you are altering the schema of the table in code you have not shown us)