diff --git a/script/static-checks/static-checks-banned-apis.sh b/script/static-checks/static-checks-banned-apis.sh
index 4bab6a7..424bbcb 100755
--- a/script/static-checks/static-checks-banned-apis.sh
+++ b/script/static-checks/static-checks-banned-apis.sh
@@ -17,7 +17,7 @@
   echo "# Check for banned APIs in the patch"
   TEST_CASE="Banned API check on patch(es)"
   "$CI_ROOT/script/static-checks/check-banned-api.py" --tree "$1" \
-      --patch --from-ref $(get_merge_base) \
+      --patch --from-ref ${merge_base} \
       &> "$LOG_FILE"
 else
   echo "# Check for banned APIs in entire source tree"
diff --git a/script/static-checks/static-checks-check-copyright.sh b/script/static-checks/static-checks-check-copyright.sh
index 9759b5f..522bbe8 100755
--- a/script/static-checks/static-checks-check-copyright.sh
+++ b/script/static-checks/static-checks-check-copyright.sh
@@ -19,7 +19,7 @@
 
 LOG_FILE=`mktemp -t common.XXXX`
 
-"$CI_ROOT"/script/static-checks/check-copyright.py --tree "$DIRECTORY" --patch --from-ref $(get_merge_base) &> "$LOG_FILE"
+"$CI_ROOT"/script/static-checks/check-copyright.py --tree "$DIRECTORY" --patch --from-ref ${merge_base} &> "$LOG_FILE"
 RES=$?
 
 if [ -s "$LOG_FILE" ]; then
diff --git a/script/static-checks/static-checks-coding-style-line-endings.sh b/script/static-checks/static-checks-coding-style-line-endings.sh
index 9c0cda7..8dddace 100755
--- a/script/static-checks/static-checks-coding-style-line-endings.sh
+++ b/script/static-checks/static-checks-coding-style-line-endings.sh
@@ -20,7 +20,7 @@
 if [[ "$2" == "patch" ]]; then
     cd "$1"
     shopt -s globstar
-    parent=$(get_merge_base)
+    parent=${merge_base}
     git diff $parent..HEAD --no-ext-diff --unified=0 --exit-code -a \
       --no-prefix **/*.{S,c,h,i,dts,dtsi,rst,mk} Makefile | \
       awk '/^\+/ && /\r$/' &> "$LOG_FILE"
diff --git a/script/static-checks/static-checks-coding-style.sh b/script/static-checks/static-checks-coding-style.sh
index 4483b15..9ff51cf 100755
--- a/script/static-checks/static-checks-coding-style.sh
+++ b/script/static-checks/static-checks-coding-style.sh
@@ -24,7 +24,7 @@
 chmod +x $CI_ROOT/script/static-checks/checkpatch.pl
 
 CHECKPATCH=$CI_ROOT/script/static-checks/checkpatch.pl \
-  make checkpatch BASE_COMMIT=$(get_merge_base) &> "$LOG_FILE"
+  make checkpatch BASE_COMMIT=${merge_base} &> "$LOG_FILE"
 RES=$?
 
 if [[ "$RES" == 0 ]]; then
diff --git a/script/static-checks/static-checks-cpu-erratum-order.sh b/script/static-checks/static-checks-cpu-erratum-order.sh
index 89b5fa0..8631c48 100755
--- a/script/static-checks/static-checks-cpu-erratum-order.sh
+++ b/script/static-checks/static-checks-cpu-erratum-order.sh
@@ -14,7 +14,7 @@
   TEST_CASE="Checking ascending order of CPU ERRATUM and CVE in the patch series"
   echo "# $TEST_CASE"
   "$CI_ROOT/script/static-checks/static-checks-cpu-erratum-order.py" --tree "$1" \
-      --patch --from-ref $(get_merge_base) &> "$LOG_FILE"
+      --patch --from-ref ${merge_base} &> "$LOG_FILE"
 else
   TEST_CASE="Checking ascending order of CPU ERRATUM and CVE in the entire source tree"
   echo "# $TEST_CASE"
diff --git a/script/static-checks/static-checks-detect-newly-added-files.sh b/script/static-checks/static-checks-detect-newly-added-files.sh
index 5b85ce6..008a147 100755
--- a/script/static-checks/static-checks-detect-newly-added-files.sh
+++ b/script/static-checks/static-checks-detect-newly-added-files.sh
@@ -60,7 +60,7 @@
   echo "# Check to detect whether newly added files are analysed by Coverity in the patch"
   TEST_CASE="Newly added files detection check for Coverity Scan analysis on patch(es)"
 # Extracting newly added source files added between commits.
-  git diff $(get_merge_base)..HEAD --name-only --diff-filter=A "*.c" &> "$TFA_PATCH_NEWFILES_LIST"
+  git diff ${merge_base}..HEAD --name-only --diff-filter=A "*.c" &> "$TFA_PATCH_NEWFILES_LIST"
   if [ -s "$TFA_PATCH_NEWFILES_LIST" ]
   then
     file_updation_report
diff --git a/script/static-checks/static-checks-include-order.sh b/script/static-checks/static-checks-include-order.sh
index 364929c..21fcb72 100755
--- a/script/static-checks/static-checks-include-order.sh
+++ b/script/static-checks/static-checks-include-order.sh
@@ -17,7 +17,7 @@
   TEST_CASE="Order of includes on the patch series"
   echo "# $TEST_CASE"
   "$CI_ROOT/script/static-checks/check-include-order.py" --tree "$1" \
-      --patch --from-ref $(get_merge_base) \
+      --patch --from-ref ${merge_base} \
       &> "$LOG_FILE"
 else
   echo "# Check order of includes of the entire source tree"
diff --git a/script/static-checks/static-checks.sh b/script/static-checks/static-checks.sh
index fe2f7b0..c805e14 100755
--- a/script/static-checks/static-checks.sh
+++ b/script/static-checks/static-checks.sh
@@ -17,7 +17,31 @@
 
 . $CI_ROOT/script/static-checks/common.sh
 
-# Initialize log file
+merge_base=$(get_merge_base)
+if [[ -z "$merge_base" ]]; then
+    echo "Failed to find merge base, fetching entire change history"
+
+    # Set GERRIT_REFSPEC if not already defined
+    if [[ -z "$GERRIT_REFSPEC" ]]; then
+        if [[ "$TF_GERRIT_PROJECT" == *tf-a-tests ]]; then
+            GERRIT_REFSPEC="$TFTF_GERRIT_REFSPEC"
+        else
+            GERRIT_REFSPEC="$TF_GERRIT_REFSPEC"
+        fi
+    fi
+
+    git fetch --depth=100 origin "$GERRIT_REFSPEC"
+    git checkout FETCH_HEAD
+
+    merge_base=$(get_merge_base)
+
+    if [[ -z "$merge_base" ]]; then
+        echo "Failed to determine merge base after fetching. Exiting." >&2
+        exit 1
+    fi
+fi
+
+export merge_base
 
 export LOG_TEST_FILENAME=$(pwd)/static-checks.log
 
@@ -29,10 +53,11 @@
 echo >> "$LOG_TEST_FILENAME"
 
 echo "Patch series being checked:" >> "$LOG_TEST_FILENAME"
-git log --oneline $(get_merge_base)..HEAD >> "$LOG_TEST_FILENAME"
+git log --oneline ${merge_base}..HEAD >> "$LOG_TEST_FILENAME"
 echo >> "$LOG_TEST_FILENAME"
 echo "Base branch reference commit:" >> "$LOG_TEST_FILENAME"
-git log --oneline -1 $(get_merge_base) >> "$LOG_TEST_FILENAME"
+git log --oneline -1 ${merge_base} >> "$LOG_TEST_FILENAME"
+
 
 echo >> "$LOG_TEST_FILENAME"