diff --git a/MANIFEST.in b/MANIFEST.in
index 8c8f62c5..f0382ab2 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -10,5 +10,6 @@ exclude .flake8
 exclude .gitignore
 exclude .pre-commit-config.yaml
 exclude .readthedocs.yml
+exclude .ruff.toml
 include *.md
 include *.py
diff --git a/iris_grib/_iris_mercator_support.py b/iris_grib/_iris_mercator_support.py
deleted file mode 100644
index 92df804d..00000000
--- a/iris_grib/_iris_mercator_support.py
+++ /dev/null
@@ -1,25 +0,0 @@
-# Copyright iris-grib contributors
-#
-# This file is part of iris-grib and is released under the BSD license.
-# See LICENSE in the root of the repository for full licensing details.
-"""
-Temporary module to check for the extended Mercator class in Iris,
-which iris-grib requires for its Mercator support.
-
-"""
-
-from packaging.version import Version
-
-import iris
-
-
-def confirm_extended_mercator_supported():
-    # Check that Iris version is at least 2.1, required for 'standard_parallel'
-    # support in the Mercator coord-system.
-    # This is a temporary fix allowing us to state Iris>=2.0 as a dependency,
-    # required for this release because Iris 2.1 is not yet available.
-    iris_version = Version(iris.__version__)
-    min_mercator_version = Version("2.1.0")
-    if iris_version < min_mercator_version:
-        msg = "Support for Mercator projections requires Iris version >= {}"
-        raise ValueError(msg.format(min_mercator_version))